21665937207026 has 16 divisors (see below), whose sum is σ = 37295721196800. Its totient is φ = 9246873021120.

The previous prime is 21665937207017. The next prime is 21665937207041. The reversal of 21665937207026 is 62070273956612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3210716426 + ... + 3210723173.

It is an arithmetic number, because the mean of its divisors is an integer number (2330982574800).

Almost surely, 2^{21665937207026} is an apocalyptic number.

21665937207026 is a deficient number, since it is larger than the sum of its proper divisors (15629783989774).

21665937207026 is a wasteful number, since it uses less digits than its factorization.

21665937207026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6421439849.

The product of its (nonzero) digits is 11430720, while the sum is 56.

The spelling of 21665937207026 in words is "twenty-one trillion, six hundred sixty-five billion, nine hundred thirty-seven million, two hundred seven thousand, twenty-six".