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20786381 = 711269953
BaseRepresentation
bin100111101001…
…0110011001101
31110010001112222
41033102303031
520310131011
62021305125
7341452460
oct117226315
943101488
1020786381
1110808130
126b651a5
1343ca345
142a912d7
151c58ddb
hex13d2ccd

20786381 has 8 divisors (see below), whose sum is σ = 25915584. Its totient is φ = 16197120.

The previous prime is 20786377. The next prime is 20786407. The reversal of 20786381 is 18368702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20786381 - 22 = 20786377 is a prime.

It is a super-2 number, since 2×207863812 = 864147270154322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20786321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134900 + ... + 135053.

It is an arithmetic number, because the mean of its divisors is an integer number (3239448).

Almost surely, 220786381 is an apocalyptic number.

It is an amenable number.

20786381 is a deficient number, since it is larger than the sum of its proper divisors (5129203).

20786381 is a wasteful number, since it uses less digits than its factorization.

20786381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269971.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 20786381 is about 4559.2083742685. The cubic root of 20786381 is about 274.9537376724.

The spelling of 20786381 in words is "twenty million, seven hundred eighty-six thousand, three hundred eighty-one".

Divisors: 1 7 11 77 269953 1889671 2969483 20786381