72657731 has 8 divisors (see below), whose sum is σ = 76010400. Its totient is φ = 69361600.

The previous prime is 72657719. The next prime is 72657763. The reversal of 72657731 is 13775627.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72657731 is a prime.

It is a super-2 number, since 2×72657731² = 10558291748136722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72657701) 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, 11495 + ... + 16656.

It is an arithmetic number, because the mean of its divisors is an integer number (9501300).

Almost surely, 2^72657731 is an apocalyptic number.

72657731 is a deficient number, since it is larger than the sum of its proper divisors (3352669).

72657731 is a wasteful number, since it uses less digits than its factorization.

72657731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28269.

The product of its digits is 61740, while the sum is 38.

The square root of 72657731 is about 8523.9504339244. The cubic root of 72657731 is about 417.2797188562.

The spelling of 72657731 in words is "seventy-two million, six hundred fifty-seven thousand, seven hundred thirty-one".