72155601 has 12 divisors (see below), whose sum is σ = 119114112. Its totient is φ = 41231736.

The previous prime is 72155543. The next prime is 72155621. The reversal of 72155601 is 10655127.

72155601 is a `hidden beast` number, since 7 + 2 + 1 + 55 + 601 = 666.

It is not a de Polignac number, because 72155601 - 2⁶ = 72155537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72155621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 572601 + ... + 572726.

It is an arithmetic number, because the mean of its divisors is an integer number (9926176).

Almost surely, 2^72155601 is an apocalyptic number.

It is an amenable number.

72155601 is a deficient number, since it is larger than the sum of its proper divisors (46958511).

72155601 is a wasteful number, since it uses less digits than its factorization.

72155601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1145340 (or 1145337 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The square root of 72155601 is about 8494.4453026669. The cubic root of 72155601 is about 416.3162370582.

The spelling of 72155601 in words is "seventy-two million, one hundred fifty-five thousand, six hundred one".