72157140821 has 2 divisors, whose sum is σ = 72157140822. Its totient is φ = 72157140820.

The previous prime is 72157140779. The next prime is 72157140871. The reversal of 72157140821 is 12804175127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51840914596 + 20316226225 = 227686^2 + 142535^2 .

It is a cyclic number.

It is not a de Polignac number, because 72157140821 - 2¹⁰ = 72157139797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72157140871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36078570410 + 36078570411.

It is an arithmetic number, because the mean of its divisors is an integer number (36078570411).

Almost surely, 2^72157140821 is an apocalyptic number.

It is an amenable number.

72157140821 is a deficient number, since it is larger than the sum of its proper divisors (1).

72157140821 is an equidigital number, since it uses as much as digits as its factorization.

72157140821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31360, while the sum is 38.

The spelling of 72157140821 in words is "seventy-two billion, one hundred fifty-seven million, one hundred forty thousand, eight hundred twenty-one".