21957064 has 24 divisors (see below), whose sum is σ = 43738290. Its totient is φ = 10331648.

The previous prime is 21957053. The next prime is 21957071. The reversal of 21957064 is 46075912.

It can be written as a sum of positive squares in 3 ways, for example, as 18922500 + 3034564 = 4350^2 + 1742^2 .

It is a super-2 number, since 2×21957064² = 964225319000192, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34).

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 5 ways as a sum of consecutive naturals, for example, 2437 + ... + 7060.

Almost surely, 2^21957064 is an apocalyptic number.

It is an amenable number.

21957064 is a deficient number, since it is larger than the sum of its proper divisors (21781226).

21957064 is a wasteful number, since it uses less digits than its factorization.

21957064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9537 (or 9516 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 21957064 is about 4685.8365315064. The cubic root of 21957064 is about 280.0215289569.

The spelling of 21957064 in words is "twenty-one million, nine hundred fifty-seven thousand, sixty-four".