21967918215 has 16 divisors (see below), whose sum is σ = 35151277536. Its totient is φ = 11715353600.

The previous prime is 21967918207. The next prime is 21967918243. The reversal of 21967918215 is 51281976912.

It is not a de Polignac number, because 21967918215 - 2³ = 21967918207 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 189955 + ... + 282875.

It is an arithmetic number, because the mean of its divisors is an integer number (2196954846).

Almost surely, 2^21967918215 is an apocalyptic number.

21967918215 is a deficient number, since it is larger than the sum of its proper divisors (13183359321).

21967918215 is a wasteful number, since it uses less digits than its factorization.

21967918215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108690.

The product of its digits is 544320, while the sum is 51.

The spelling of 21967918215 in words is "twenty-one billion, nine hundred sixty-seven million, nine hundred eighteen thousand, two hundred fifteen".