21952618 has 16 divisors (see below), whose sum is σ = 34610400. Its totient is φ = 10429776.

The previous prime is 21952613. The next prime is 21952631. The reversal of 21952618 is 81625912.

It is not an unprimeable number, because it can be changed into a prime (21952613) 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, 268 + ... + 6631.

It is an arithmetic number, because the mean of its divisors is an integer number (2163150).

Almost surely, 2^21952618 is an apocalyptic number.

21952618 is a deficient number, since it is larger than the sum of its proper divisors (12657782).

21952618 is a wasteful number, since it uses less digits than its factorization.

21952618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6981.

The product of its digits is 8640, while the sum is 34.

The square root of 21952618 is about 4685.3620991339. The cubic root of 21952618 is about 280.0026275264.

The spelling of 21952618 in words is "twenty-one million, nine hundred fifty-two thousand, six hundred eighteen".