21508840716402 has 64 divisors (see below), whose sum is σ = 47077851421440. Its totient is φ = 6511657334784.

The previous prime is 21508840716379. The next prime is 21508840716409. The reversal of 21508840716402 is 20461704880512.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21508840716409) 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, 7698702 + ... + 10113737.

It is an arithmetic number, because the mean of its divisors is an integer number (735591428460).

Almost surely, 2^{21508840716402} is an apocalyptic number.

21508840716402 is an abundant number, since it is smaller than the sum of its proper divisors (25569010705038).

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

21508840716402 is a wasteful number, since it uses less digits than its factorization.

21508840716402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17812707.

The product of its (nonzero) digits is 860160, while the sum is 48.

The spelling of 21508840716402 in words is "twenty-one trillion, five hundred eight billion, eight hundred forty million, seven hundred sixteen thousand, four hundred two".