72499813 has 4 divisors (see below), whose sum is σ = 73867788. Its totient is φ = 71131840.

The previous prime is 72499807. The next prime is 72499831. The reversal of 72499813 is 31899427.

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 22118209 + 50381604 = 4703^2 + 7098^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72499813 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72499813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72499873) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 683908 + ... + 684013.

It is an arithmetic number, because the mean of its divisors is an integer number (18466947).

Almost surely, 2^72499813 is an apocalyptic number.

It is an amenable number.

72499813 is a deficient number, since it is larger than the sum of its proper divisors (1367975).

72499813 is a wasteful number, since it uses less digits than its factorization.

72499813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1367974.

The product of its digits is 108864, while the sum is 43.

The square root of 72499813 is about 8514.6822019380. The cubic root of 72499813 is about 416.9771872650.

The spelling of 72499813 in words is "seventy-two million, four hundred ninety-nine thousand, eight hundred thirteen".