72397661 has 16 divisors (see below), whose sum is σ = 84564480. Its totient is φ = 60698160.

The previous prime is 72397649. The next prime is 72397693. The reversal of 72397661 is 16679327.

It is a cyclic number.

It is not a de Polignac number, because 72397661 - 2⁶ = 72397597 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72397561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126506 + ... + 127076.

It is an arithmetic number, because the mean of its divisors is an integer number (5285280).

Almost surely, 2^72397661 is an apocalyptic number.

It is an amenable number.

72397661 is a deficient number, since it is larger than the sum of its proper divisors (12166819).

72397661 is a wasteful number, since it uses less digits than its factorization.

72397661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 944.

The product of its digits is 95256, while the sum is 41.

The square root of 72397661 is about 8508.6815077308. The cubic root of 72397661 is about 416.7812553815.

The spelling of 72397661 in words is "seventy-two million, three hundred ninety-seven thousand, six hundred sixty-one".