21013758408 has 32 divisors (see below), whose sum is σ = 53756128800. Its totient is φ = 6841688448.

The previous prime is 21013758401. The next prime is 21013758439. The reversal of 21013758408 is 80485731012.

It is not an unprimeable number, because it can be changed into a prime (21013758401) 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, 10180053 + ... + 10182116.

It is an arithmetic number, because the mean of its divisors is an integer number (1679879025).

Almost surely, 2^21013758408 is an apocalyptic number.

It is an amenable number.

21013758408 is an abundant number, since it is smaller than the sum of its proper divisors (32742370392).

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

21013758408 is a wasteful number, since it uses less digits than its factorization.

21013758408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20362221 (or 20362217 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 39.

The spelling of 21013758408 in words is "twenty-one billion, thirteen million, seven hundred fifty-eight thousand, four hundred eight".