72661800815 has 16 divisors (see below), whose sum is σ = 87426625536. Its totient is φ = 57974560800.

The previous prime is 72661800787. The next prime is 72661800817. The reversal of 72661800815 is 51800816627.

It is a happy number.

It is not a de Polignac number, because 72661800815 - 2²⁴ = 72645023599 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 (72661800817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11786924 + ... + 11793086.

It is an arithmetic number, because the mean of its divisors is an integer number (5464164096).

Almost surely, 2^72661800815 is an apocalyptic number.

72661800815 is a deficient number, since it is larger than the sum of its proper divisors (14764824721).

72661800815 is a wasteful number, since it uses less digits than its factorization.

72661800815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12070.

The product of its (nonzero) digits is 161280, while the sum is 44.

It can be divided in two parts, 7266 and 1800815, that added together give a palindrome (1808081).

The spelling of 72661800815 in words is "seventy-two billion, six hundred sixty-one million, eight hundred thousand, eight hundred fifteen".