72720667172177 has 4 divisors (see below), whose sum is σ = 72731992621236. Its totient is φ = 72709341723120.

The previous prime is 72720667172159. The next prime is 72720667172189. The reversal of 72720667172177 is 77127176602727.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 36390923535121 + 36329743637056 = 6032489^2 + 6027416^2 .

It is a cyclic number.

It is not a de Polignac number, because 72720667172177 - 2¹⁴ = 72720667155793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72720667178177) 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, 5662714898 + ... + 5662727739.

It is an arithmetic number, because the mean of its divisors is an integer number (18182998155309).

Almost surely, 2^{72720667172177} is an apocalyptic number.

It is an amenable number.

72720667172177 is a deficient number, since it is larger than the sum of its proper divisors (11325449059).

72720667172177 is a wasteful number, since it uses less digits than its factorization.

72720667172177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11325449058.

The product of its (nonzero) digits is 33882912, while the sum is 62.

The spelling of 72720667172177 in words is "seventy-two trillion, seven hundred twenty billion, six hundred sixty-seven million, one hundred seventy-two thousand, one hundred seventy-seven".