2172581665024 has 81 divisors (see below), whose sum is σ = 4607631386337. Its totient is φ = 1022202703872.

The previous prime is 2172581665021. The next prime is 2172581665049. The reversal of 2172581665024 is 4205661852712.

The square root of 2172581665024 is 1473968.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1691456313600 + 481125351424 = 1300560^2 + 693632^2 .

It is a super-2 number, since 2×2172581665024² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2172581665021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 400916587 + ... + 400922005.

Almost surely, 2^{2172581665024} is an apocalyptic number.

2172581665024 is the 1473968-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2172581665024

2172581665024 is an abundant number, since it is smaller than the sum of its proper divisors (2435049721313).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2172581665024 is an frugal number, since it uses more digits than its factorization.

2172581665024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10888 (or 5438 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 49.

Multiplying 2172581665024 by its sum of digits (49), we get a square (106456501586176 = 10317776²).

The spelling of 2172581665024 in words is "two trillion, one hundred seventy-two billion, five hundred eighty-one million, six hundred sixty-five thousand, twenty-four".