72558721 has 8 divisors (see below), whose sum is σ = 75962880. Its totient is φ = 69175392.

The previous prime is 72558713. The next prime is 72558743. The reversal of 72558721 is 12785527.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 72558721 - 2³ = 72558713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72558751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2160 + ... + 12238.

It is an arithmetic number, because the mean of its divisors is an integer number (9495360).

Almost surely, 2^72558721 is an apocalyptic number.

It is an amenable number.

72558721 is a deficient number, since it is larger than the sum of its proper divisors (3404159).

72558721 is a wasteful number, since it uses less digits than its factorization.

72558721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10415.

The product of its digits is 39200, while the sum is 37.

The square root of 72558721 is about 8518.1407008807. The cubic root of 72558721 is about 417.0900916591.

The spelling of 72558721 in words is "seventy-two million, five hundred fifty-eight thousand, seven hundred twenty-one".