21953612 has 6 divisors (see below), whose sum is σ = 38418828. Its totient is φ = 10976804.

The previous prime is 21953587. The next prime is 21953621. The reversal of 21953612 is 21635912.

It is a super-2 number, since 2×21953612² = 963922159693088, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2744198 + ... + 2744205.

It is an arithmetic number, because the mean of its divisors is an integer number (6403138).

Almost surely, 2^21953612 is an apocalyptic number.

It is an amenable number.

21953612 is a deficient number, since it is larger than the sum of its proper divisors (16465216).

21953612 is a wasteful number, since it uses less digits than its factorization.

21953612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5488407 (or 5488405 counting only the distinct ones).

The product of its digits is 3240, while the sum is 29.

The square root of 21953612 is about 4685.4681729791. The cubic root of 21953612 is about 280.0068535737.

The spelling of 21953612 in words is "twenty-one million, nine hundred fifty-three thousand, six hundred twelve".