72145557 has 12 divisors (see below), whose sum is σ = 113684064. Its totient is φ = 43724520.

The previous prime is 72145553. The next prime is 72145559. The reversal of 72145557 is 75554127.

It is not a de Polignac number, because 72145557 - 2² = 72145553 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72145553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 364273 + ... + 364470.

It is an arithmetic number, because the mean of its divisors is an integer number (9473672).

Almost surely, 2^72145557 is an apocalyptic number.

It is an amenable number.

72145557 is a deficient number, since it is larger than the sum of its proper divisors (41538507).

72145557 is a wasteful number, since it uses less digits than its factorization.

72145557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 728760 (or 728757 counting only the distinct ones).

The product of its digits is 49000, while the sum is 36.

The square root of 72145557 is about 8493.8540722101. The cubic root of 72145557 is about 416.2969192032.

The spelling of 72145557 in words is "seventy-two million, one hundred forty-five thousand, five hundred fifty-seven".