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20971380 = 22351931811
BaseRepresentation
bin100111111111…
…1111101110100
31110110110022210
41033333331310
520332041010
62025253420
7343153023
oct117777564
943413283
1020971380
1110924121
127034270
134463601
142adc8ba
151c93b20
hex13fff74

20971380 has 48 divisors (see below), whose sum is σ = 59056704. Its totient is φ = 5560320.

The previous prime is 20971297. The next prime is 20971381. The reversal of 20971380 is 8317902.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20971381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10675 + ... + 12485.

It is an arithmetic number, because the mean of its divisors is an integer number (1230348).

Almost surely, 220971380 is an apocalyptic number.

20971380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20971380 is an abundant number, since it is smaller than the sum of its proper divisors (38085324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20971380 is a wasteful number, since it uses less digits than its factorization.

20971380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2016 (or 2014 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 20971380 is about 4579.4519322731. The cubic root of 20971380 is about 275.7670266735.

The spelling of 20971380 in words is "twenty million, nine hundred seventy-one thousand, three hundred eighty".

Divisors: 1 2 3 4 5 6 10 12 15 20 30 60 193 386 579 772 965 1158 1811 1930 2316 2895 3622 3860 5433 5790 7244 9055 10866 11580 18110 21732 27165 36220 54330 108660 349523 699046 1048569 1398092 1747615 2097138 3495230 4194276 5242845 6990460 10485690 20971380