21391064873722 has 16 divisors (see below), whose sum is σ = 32409442490112. Its totient is φ = 10587951077200.

The previous prime is 21391064873707. The next prime is 21391064873743. The reversal of 21391064873722 is 22737846019312.

It is a super-2 number, since 2×21391064873722² (a number of 27 digits) contains 22 as substring.

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, 7151878 + ... + 9691825.

It is an arithmetic number, because the mean of its divisors is an integer number (2025590155632).

Almost surely, 2^{21391064873722} is an apocalyptic number.

21391064873722 is a deficient number, since it is larger than the sum of its proper divisors (11018377616390).

21391064873722 is a wasteful number, since it uses less digits than its factorization.

21391064873722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16850093.

The product of its (nonzero) digits is 6096384, while the sum is 55.

The spelling of 21391064873722 in words is "twenty-one trillion, three hundred ninety-one billion, sixty-four million, eight hundred seventy-three thousand, seven hundred twenty-two".