72252121640 has 16 divisors (see below), whose sum is σ = 162567273780. Its totient is φ = 28900848640.

The previous prime is 72252121621. The next prime is 72252121649. The reversal of 72252121640 is 4612125227.

It can be written as a sum of positive squares in 2 ways, for example, as 71501690404 + 750431236 = 267398^2 + 27394^2 .

It is a junction number, because it is equal to n+sod(n) for n = 72252121597 and 72252121606.

It is not an unprimeable number, because it can be changed into a prime (72252121649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 903151481 + ... + 903151560.

Almost surely, 2^72252121640 is an apocalyptic number.

It is an amenable number.

72252121640 is an abundant number, since it is smaller than the sum of its proper divisors (90315152140).

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

72252121640 is a wasteful number, since it uses less digits than its factorization.

72252121640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1806303052 (or 1806303048 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 32.

Adding to 72252121640 its reverse (4612125227), we get a palindrome (76864246867).

The spelling of 72252121640 in words is "seventy-two billion, two hundred fifty-two million, one hundred twenty-one thousand, six hundred forty".