21164542377985 has 32 divisors (see below), whose sum is σ = 26579324862720. Its totient is φ = 16148073004800.

The previous prime is 21164542377971. The next prime is 21164542377989. The reversal of 21164542377985 is 58977324546112.

It is not a de Polignac number, because 21164542377985 - 2²¹ = 21164540280833 is a prime.

It is a super-2 number, since 2×21164542377985² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21164542377989) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 89554275 + ... + 89790295.

It is an arithmetic number, because the mean of its divisors is an integer number (830603901960).

Almost surely, 2^{21164542377985} is an apocalyptic number.

It is an amenable number.

21164542377985 is a deficient number, since it is larger than the sum of its proper divisors (5414782484735).

21164542377985 is a wasteful number, since it uses less digits than its factorization.

21164542377985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238329.

The product of its digits is 101606400, while the sum is 64.

The spelling of 21164542377985 in words is "twenty-one trillion, one hundred sixty-four billion, five hundred forty-two million, three hundred seventy-seven thousand, nine hundred eighty-five".