72721293965 has 16 divisors (see below), whose sum is σ = 87568176816. Its totient is φ = 57975590400.

The previous prime is 72721293961. The next prime is 72721293971. The reversal of 72721293965 is 56939212727.

It can be written as a sum of positive squares in 8 ways, for example, as 2085474889 + 70635819076 = 45667^2 + 265774^2 .

It is not a de Polignac number, because 72721293965 - 2² = 72721293961 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 (72721293961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1962449 + ... + 1999161.

It is an arithmetic number, because the mean of its divisors is an integer number (5473011051).

Almost surely, 2^72721293965 is an apocalyptic number.

It is an amenable number.

72721293965 is a deficient number, since it is larger than the sum of its proper divisors (14846882851).

72721293965 is a wasteful number, since it uses less digits than its factorization.

72721293965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38080.

The product of its digits is 2857680, while the sum is 53.

The spelling of 72721293965 in words is "seventy-two billion, seven hundred twenty-one million, two hundred ninety-three thousand, nine hundred sixty-five".