72744521 has 4 divisors (see below), whose sum is σ = 76573200. Its totient is φ = 68915844.

The previous prime is 72744517. The next prime is 72744523. The reversal of 72744521 is 12544727.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72744521 - 2² = 72744517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72744523) 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, 1914311 + ... + 1914348.

It is an arithmetic number, because the mean of its divisors is an integer number (19143300).

Almost surely, 2^72744521 is an apocalyptic number.

It is an amenable number.

72744521 is a deficient number, since it is larger than the sum of its proper divisors (3828679).

72744521 is a wasteful number, since it uses less digits than its factorization.

72744521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3828678.

The product of its digits is 15680, while the sum is 32.

The square root of 72744521 is about 8529.0398639003. The cubic root of 72744521 is about 417.4458002717.

The spelling of 72744521 in words is "seventy-two million, seven hundred forty-four thousand, five hundred twenty-one".