21808650715 has 36 divisors (see below), whose sum is σ = 27997164144. Its totient is φ = 16277542336.

The previous prime is 21808650709. The next prime is 21808650733. The reversal of 21808650715 is 51705680812.

It is not a de Polignac number, because 21808650715 - 2²⁵ = 21775096283 is a prime.

It is a super-2 number, since 2×21808650715² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 74432109 + ... + 74432401.

It is an arithmetic number, because the mean of its divisors is an integer number (777699004).

Almost surely, 2^21808650715 is an apocalyptic number.

21808650715 is a deficient number, since it is larger than the sum of its proper divisors (6188513429).

21808650715 is an frugal number, since it uses more digits than its factorization.

21808650715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708 (or 368 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 43.

The spelling of 21808650715 in words is "twenty-one billion, eight hundred eight million, six hundred fifty thousand, seven hundred fifteen".