21550715715 has 8 divisors (see below), whose sum is σ = 34481145168. Its totient is φ = 11493715040.

The previous prime is 21550715707. The next prime is 21550715717. The reversal of 21550715715 is 51751705512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21550715715 - 2³ = 21550715707 is a prime.

It is a super-2 number, since 2×21550715715² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21550715717) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 718357176 + ... + 718357205.

It is an arithmetic number, because the mean of its divisors is an integer number (4310143146).

Almost surely, 2^21550715715 is an apocalyptic number.

21550715715 is a deficient number, since it is larger than the sum of its proper divisors (12930429453).

21550715715 is a wasteful number, since it uses less digits than its factorization.

21550715715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1436714389.

The product of its (nonzero) digits is 61250, while the sum is 39.

The spelling of 21550715715 in words is "twenty-one billion, five hundred fifty million, seven hundred fifteen thousand, seven hundred fifteen".