21958038 has 12 divisors (see below), whose sum is σ = 47575788. Its totient is φ = 7319340.

The previous prime is 21958037. The next prime is 21958039. The reversal of 21958038 is 83085912.

It is an interprime number because it is at equal distance from previous prime (21958037) and next prime (21958039).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21957993 and 21958011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21958037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 609928 + ... + 609963.

It is an arithmetic number, because the mean of its divisors is an integer number (3964649).

Almost surely, 2^21958038 is an apocalyptic number.

21958038 is an abundant number, since it is smaller than the sum of its proper divisors (25617750).

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

21958038 is a wasteful number, since it uses less digits than its factorization.

21958038 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1219899 (or 1219896 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 21958038 is about 4685.9404605693. The cubic root of 21958038 is about 280.0256694154.

The spelling of 21958038 in words is "twenty-one million, nine hundred fifty-eight thousand, thirty-eight".