72055521 has 16 divisors (see below), whose sum is σ = 107809920. Its totient is φ = 47559600.

The previous prime is 72055513. The next prime is 72055523. The reversal of 72055521 is 12555027.

It is a happy number.

It is not a de Polignac number, because 72055521 - 2³ = 72055513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (72055523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10485 + ... + 15938.

It is an arithmetic number, because the mean of its divisors is an integer number (6738120).

Almost surely, 2^72055521 is an apocalyptic number.

It is an amenable number.

72055521 is a deficient number, since it is larger than the sum of its proper divisors (35754399).

72055521 is a wasteful number, since it uses less digits than its factorization.

72055521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26533 (or 26527 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 27.

The square root of 72055521 is about 8488.5523500771. The cubic root of 72055521 is about 416.1236707783.

The spelling of 72055521 in words is "seventy-two million, fifty-five thousand, five hundred twenty-one".