21237775215 has 16 divisors (see below), whose sum is σ = 35979290208. Its totient is φ = 10660530176.

The previous prime is 21237775199. The next prime is 21237775219. The reversal of 21237775215 is 51257773212.

It is a cyclic number.

It is not a de Polignac number, because 21237775215 - 2⁴ = 21237775199 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21237775219) 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, 41642442 + ... + 41642951.

It is an arithmetic number, because the mean of its divisors is an integer number (2248705638).

Almost surely, 2^21237775215 is an apocalyptic number.

21237775215 is a deficient number, since it is larger than the sum of its proper divisors (14741514993).

21237775215 is a wasteful number, since it uses less digits than its factorization.

21237775215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83285418.

The product of its digits is 205800, while the sum is 42.

The spelling of 21237775215 in words is "twenty-one billion, two hundred thirty-seven million, seven hundred seventy-five thousand, two hundred fifteen".