72999912961 has 4 divisors (see below), whose sum is σ = 73033821252. Its totient is φ = 72966004672.

The previous prime is 72999912943. The next prime is 72999912971. The reversal of 72999912961 is 16921999927.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16921999927 = 7 ⋅2417428561.

It can be written as a sum of positive squares in 2 ways, for example, as 23918169025 + 49081743936 = 154655^2 + 221544^2 .

It is a cyclic number.

It is not a de Polignac number, because 72999912961 - 2¹⁹ = 72999388673 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72999912893 and 72999912902.

It is not an unprimeable number, because it can be changed into a prime (72999912971) 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, 16950916 + ... + 16955221.

It is an arithmetic number, because the mean of its divisors is an integer number (18258455313).

Almost surely, 2^72999912961 is an apocalyptic number.

It is an amenable number.

72999912961 is a deficient number, since it is larger than the sum of its proper divisors (33908291).

72999912961 is a wasteful number, since it uses less digits than its factorization.

72999912961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33908290.

The product of its digits is 9920232, while the sum is 64.

The spelling of 72999912961 in words is "seventy-two billion, nine hundred ninety-nine million, nine hundred twelve thousand, nine hundred sixty-one".