72710521 has 24 divisors (see below), whose sum is σ = 83458760. Its totient is φ = 62954496.

The previous prime is 72710509. The next prime is 72710527. The reversal of 72710521 is 12501727.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5290000 + 67420521 = 2300^2 + 8211^2 .

It is a de Polignac number, because none of the positive numbers 2^k-72710521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72710527) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 667015 + ... + 667123.

Almost surely, 2^72710521 is an apocalyptic number.

It is an amenable number.

72710521 is a deficient number, since it is larger than the sum of its proper divisors (10748239).

72710521 is a wasteful number, since it uses less digits than its factorization.

72710521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 980, while the sum is 25.

The square root of 72710521 is about 8527.0464405913. The cubic root of 72710521 is about 417.3807535903.

The spelling of 72710521 in words is "seventy-two million, seven hundred ten thousand, five hundred twenty-one".