21958668 has 24 divisors (see below), whose sum is σ = 56930160. Its totient is φ = 7319520.

The previous prime is 21958639. The next prime is 21958691. The reversal of 21958668 is 86685912.

21958668 is a `hidden beast` number, since 2 + 1 + 9 + 586 + 68 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101553 + ... + 101768.

It is an arithmetic number, because the mean of its divisors is an integer number (2372090).

Almost surely, 2^21958668 is an apocalyptic number.

It is an amenable number.

21958668 is an abundant number, since it is smaller than the sum of its proper divisors (34971492).

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

21958668 is a wasteful number, since it uses less digits than its factorization.

21958668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203334 (or 203326 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 21958668 is about 4686.0076824521. The cubic root of 21958668 is about 280.0283474701.

The spelling of 21958668 in words is "twenty-one million, nine hundred fifty-eight thousand, six hundred sixty-eight".