72575721 has 12 divisors (see below), whose sum is σ = 105177072. Its totient is φ = 48224376.

The previous prime is 72575717. The next prime is 72575747. The reversal of 72575721 is 12757527.

It is not a de Polignac number, because 72575721 - 2² = 72575717 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (72575761) 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, 10371 + ... + 15896.

It is an arithmetic number, because the mean of its divisors is an integer number (8764756).

Almost surely, 2^72575721 is an apocalyptic number.

It is an amenable number.

72575721 is a deficient number, since it is larger than the sum of its proper divisors (32601351).

72575721 is a wasteful number, since it uses less digits than its factorization.

72575721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26580 (or 26577 counting only the distinct ones).

The product of its digits is 34300, while the sum is 36.

The square root of 72575721 is about 8519.1385127840. The cubic root of 72575721 is about 417.1226628776.

The spelling of 72575721 in words is "seventy-two million, five hundred seventy-five thousand, seven hundred twenty-one".