21313960 has 16 divisors (see below), whose sum is σ = 47956500. Its totient is φ = 8525568.

The previous prime is 21313951. The next prime is 21313979. The reversal of 21313960 is 6931312.

It can be written as a sum of positive squares in 2 ways, for example, as 21288996 + 24964 = 4614^2 + 158^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266385 + ... + 266464.

Almost surely, 2^21313960 is an apocalyptic number.

21313960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21313960 is an abundant number, since it is smaller than the sum of its proper divisors (26642540).

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

21313960 is a wasteful number, since it uses less digits than its factorization.

21313960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 532860 (or 532856 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 21313960 is about 4616.7044523123. The cubic root of 21313960 is about 277.2605298194.

The spelling of 21313960 in words is "twenty-one million, three hundred thirteen thousand, nine hundred sixty".