21392658 has 24 divisors (see below), whose sum is σ = 52972608. Its totient is φ = 6112152.

The previous prime is 21392641. The next prime is 21392659. The reversal of 21392658 is 85629312.

It is not an unprimeable number, because it can be changed into a prime (21392659) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 84766 + ... + 85017.

It is an arithmetic number, because the mean of its divisors is an integer number (2207192).

Almost surely, 2^21392658 is an apocalyptic number.

21392658 is an abundant number, since it is smaller than the sum of its proper divisors (31579950).

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

21392658 is a wasteful number, since it uses less digits than its factorization.

21392658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169798 (or 169795 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21392658 is about 4625.2197785619. The cubic root of 21392658 is about 277.6013557198.

The spelling of 21392658 in words is "twenty-one million, three hundred ninety-two thousand, six hundred fifty-eight".