72973321 has 2 divisors, whose sum is σ = 72973322. Its totient is φ = 72973320.

The previous prime is 72973301. The next prime is 72973339. The reversal of 72973321 is 12337927.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71639296 + 1334025 = 8464^2 + 1155^2 .

It is a cyclic number.

It is not a de Polignac number, because 72973321 - 2⁵ = 72973289 is a prime.

It is equal to p_4282576 and since 72973321 and 4282576 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (72973301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36486660 + 36486661.

It is an arithmetic number, because the mean of its divisors is an integer number (36486661).

Almost surely, 2^72973321 is an apocalyptic number.

It is an amenable number.

72973321 is a deficient number, since it is larger than the sum of its proper divisors (1).

72973321 is an equidigital number, since it uses as much as digits as its factorization.

72973321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15876, while the sum is 34.

The square root of 72973321 is about 8542.4423322607. The cubic root of 72973321 is about 417.8829999229.

The spelling of 72973321 in words is "seventy-two million, nine hundred seventy-three thousand, three hundred twenty-one".