72491439631 has 4 divisors (see below), whose sum is σ = 78067704232. Its totient is φ = 66915175032.

The previous prime is 72491439607. The next prime is 72491439641. The reversal of 72491439631 is 13693419427.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13693419427 = 105173 ⋅130199.

It is a cyclic number.

It is not a de Polignac number, because 72491439631 - 2¹⁷ = 72491308559 is a prime.

It is a super-2 number, since 2×72491439631² (a number of 23 digits) 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 (72491439641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2788132281 + ... + 2788132306.

It is an arithmetic number, because the mean of its divisors is an integer number (19516926058).

Almost surely, 2^72491439631 is an apocalyptic number.

72491439631 is a deficient number, since it is larger than the sum of its proper divisors (5576264601).

72491439631 is a wasteful number, since it uses less digits than its factorization.

72491439631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5576264600.

The product of its digits is 979776, while the sum is 49.

The spelling of 72491439631 in words is "seventy-two billion, four hundred ninety-one million, four hundred thirty-nine thousand, six hundred thirty-one".