21317907730 has 64 divisors (see below), whose sum is σ = 44872289280. Its totient is φ = 7140809664.

The previous prime is 21317907727. The next prime is 21317907739. The reversal of 21317907730 is 3770971312.

It is not an unprimeable number, because it can be changed into a prime (21317907739) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 657357 + ... + 689023.

It is an arithmetic number, because the mean of its divisors is an integer number (701129520).

Almost surely, 2^21317907730 is an apocalyptic number.

21317907730 is an abundant number, since it is smaller than the sum of its proper divisors (23554381550).

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

21317907730 is a wasteful number, since it uses less digits than its factorization.

21317907730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31903.

The product of its (nonzero) digits is 55566, while the sum is 40.

The spelling of 21317907730 in words is "twenty-one billion, three hundred seventeen million, nine hundred seven thousand, seven hundred thirty".