21680216802439 has 16 divisors (see below), whose sum is σ = 23534656838784. Its totient is φ = 19853086521600.

The previous prime is 21680216802407. The next prime is 21680216802457. The reversal of 21680216802439 is 93420861208612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21680216802439 - 2⁵ = 21680216802407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21680216802469) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12384952 + ... + 14026669.

It is an arithmetic number, because the mean of its divisors is an integer number (1470916052424).

Almost surely, 2^{21680216802439} is an apocalyptic number.

21680216802439 is a deficient number, since it is larger than the sum of its proper divisors (1854440036345).

21680216802439 is a wasteful number, since it uses less digits than its factorization.

21680216802439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26412138.

The product of its (nonzero) digits is 1990656, while the sum is 52.

The spelling of 21680216802439 in words is "twenty-one trillion, six hundred eighty billion, two hundred sixteen million, eight hundred two thousand, four hundred thirty-nine".