72499661 has 4 divisors (see below), whose sum is σ = 78076572. Its totient is φ = 66922752.

The previous prime is 72499631. The next prime is 72499663. The reversal of 72499661 is 16699427.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4024036 + 68475625 = 2006^2 + 8275^2 .

It is not a de Polignac number, because 72499661 - 2²⁶ = 5390797 is a prime.

It is a super-2 number, since 2×72499661² = 10512401690229842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72499663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2788436 + ... + 2788461.

It is an arithmetic number, because the mean of its divisors is an integer number (19519143).

Almost surely, 2^72499661 is an apocalyptic number.

It is an amenable number.

72499661 is a deficient number, since it is larger than the sum of its proper divisors (5576911).

72499661 is a wasteful number, since it uses less digits than its factorization.

72499661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5576910.

The product of its digits is 163296, while the sum is 44.

The square root of 72499661 is about 8514.6732761745. The cubic root of 72499661 is about 416.9768958593.

The spelling of 72499661 in words is "seventy-two million, four hundred ninety-nine thousand, six hundred sixty-one".