21097405698 has 16 divisors (see below), whose sum is σ = 43335212160. Its totient is φ = 6842401776.

The previous prime is 21097405627. The next prime is 21097405709. The reversal of 21097405698 is 89650479012.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21097405698.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47516458 + ... + 47516901.

It is an arithmetic number, because the mean of its divisors is an integer number (2708450760).

Almost surely, 2^21097405698 is an apocalyptic number.

21097405698 is an abundant number, since it is smaller than the sum of its proper divisors (22237806462).

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

21097405698 is a wasteful number, since it uses less digits than its factorization.

21097405698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95033401.

The product of its (nonzero) digits is 1088640, while the sum is 51.

The spelling of 21097405698 in words is "twenty-one billion, ninety-seven million, four hundred five thousand, six hundred ninety-eight".