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21265880 = 2354112967
BaseRepresentation
bin101000100011…
…1110111011000
31111000102022012
41101013313120
520421002010
62035445052
7345520436
oct121076730
944012265
1021265880
1111005409
127156788
13453767c
142b77d56
151d01005
hex1447dd8

21265880 has 32 divisors (see below), whose sum is σ = 49019040. Its totient is φ = 8298240.

The previous prime is 21265877. The next prime is 21265889. The reversal of 21265880 is 8856212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21265889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4844 + ... + 8123.

It is an arithmetic number, because the mean of its divisors is an integer number (1531845).

Almost surely, 221265880 is an apocalyptic number.

21265880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21265880 is an abundant number, since it is smaller than the sum of its proper divisors (27753160).

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

21265880 is a wasteful number, since it uses less digits than its factorization.

21265880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13019 (or 13015 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 21265880 is about 4611.4943348117. The cubic root of 21265880 is about 277.0518915586.

The spelling of 21265880 in words is "twenty-one million, two hundred sixty-five thousand, eight hundred eighty".

Divisors: 1 2 4 5 8 10 20 40 41 82 164 205 328 410 820 1640 12967 25934 51868 64835 103736 129670 259340 518680 531647 1063294 2126588 2658235 4253176 5316470 10632940 21265880