20913858 has 24 divisors (see below), whose sum is σ = 51787008. Its totient is φ = 5975352.

The previous prime is 20913857. The next prime is 20913869. The reversal of 20913858 is 85831902.

It is not an unprimeable number, because it can be changed into a prime (20913857) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 82866 + ... + 83117.

It is an arithmetic number, because the mean of its divisors is an integer number (2157792).

Almost surely, 2^20913858 is an apocalyptic number.

20913858 is an abundant number, since it is smaller than the sum of its proper divisors (30873150).

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

20913858 is a wasteful number, since it uses less digits than its factorization.

20913858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165998 (or 165995 counting only the distinct ones).

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

The square root of 20913858 is about 4573.1671738523. The cubic root of 20913858 is about 275.5146637518.

The spelling of 20913858 in words is "twenty million, nine hundred thirteen thousand, eight hundred fifty-eight".