72991615 has 8 divisors (see below), whose sum is σ = 87655968. Its totient is φ = 58349280.

The previous prime is 72991613. The next prime is 72991619. The reversal of 72991615 is 51619927.

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

It is not a de Polignac number, because 72991615 - 2¹ = 72991613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72991613) 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, 2985 + ... + 12445.

It is an arithmetic number, because the mean of its divisors is an integer number (10956996).

Almost surely, 2^72991615 is an apocalyptic number.

72991615 is a deficient number, since it is larger than the sum of its proper divisors (14664353).

72991615 is a wasteful number, since it uses less digits than its factorization.

72991615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11009.

The product of its digits is 34020, while the sum is 40.

The square root of 72991615 is about 8543.5130362164. The cubic root of 72991615 is about 417.9179173089.

The spelling of 72991615 in words is "seventy-two million, nine hundred ninety-one thousand, six hundred fifteen".