72986813 has 4 divisors (see below), whose sum is σ = 73632828. Its totient is φ = 72340800.

The previous prime is 72986807. The next prime is 72986819. The reversal of 72986813 is 31868927.

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

It is an interprime number because it is at equal distance from previous prime (72986807) and next prime (72986819).

It can be written as a sum of positive squares in 2 ways, for example, as 2393209 + 70593604 = 1547^2 + 8402^2 .

It is a cyclic number.

It is not a de Polignac number, because 72986813 - 2¹⁰ = 72985789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72986819) 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, 322838 + ... + 323063.

It is an arithmetic number, because the mean of its divisors is an integer number (18408207).

Almost surely, 2^72986813 is an apocalyptic number.

It is an amenable number.

72986813 is a deficient number, since it is larger than the sum of its proper divisors (646015).

72986813 is a wasteful number, since it uses less digits than its factorization.

72986813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646014.

The product of its digits is 145152, while the sum is 44.

The square root of 72986813 is about 8543.2319996591. The cubic root of 72986813 is about 417.9087523939.

The spelling of 72986813 in words is "seventy-two million, nine hundred eighty-six thousand, eight hundred thirteen".