72135753561 has 9 divisors (see below), whose sum is σ = 104197252341. Its totient is φ = 48089965212.

The previous prime is 72135753551. The next prime is 72135753563. The reversal of 72135753561 is 16535753127.

The square root of 72135753561 is 268581.

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

72135753561 is a `hidden beast` number, since 7 + 2 + 1 + 3 + 57 + 535 + 61 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 72135753561 - 2³¹ = 69988269913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72135753563) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 760980 + ... + 850506.

Almost surely, 2^72135753561 is an apocalyptic number.

72135753561 is the 268581-st square number.

72135753561 is the 134291-st centered octagonal number.

It is an amenable number.

72135753561 is a deficient number, since it is larger than the sum of its proper divisors (32061498780).

72135753561 is an frugal number, since it uses more digits than its factorization.

72135753561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179060 (or 89530 counting only the distinct ones).

The product of its digits is 661500, while the sum is 45.

The spelling of 72135753561 in words is "seventy-two billion, one hundred thirty-five million, seven hundred fifty-three thousand, five hundred sixty-one".