72553529921 has 2 divisors, whose sum is σ = 72553529922. Its totient is φ = 72553529920.

The previous prime is 72553529891. The next prime is 72553529929. The reversal of 72553529921 is 12992535527.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71844905521 + 708624400 = 268039^2 + 26620^2 .

It is a cyclic number.

It is not a de Polignac number, because 72553529921 - 2³⁰ = 71479788097 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72553529921.

It is not a weakly prime, because it can be changed into another prime (72553529929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36276764960 + 36276764961.

It is an arithmetic number, because the mean of its divisors is an integer number (36276764961).

Almost surely, 2^72553529921 is an apocalyptic number.

It is an amenable number.

72553529921 is a deficient number, since it is larger than the sum of its proper divisors (1).

72553529921 is an equidigital number, since it uses as much as digits as its factorization.

72553529921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1701000, while the sum is 50.

The spelling of 72553529921 in words is "seventy-two billion, five hundred fifty-three million, five hundred twenty-nine thousand, nine hundred twenty-one".