72804521 has 2 divisors, whose sum is σ = 72804522. Its totient is φ = 72804520.

The previous prime is 72804503. The next prime is 72804527. The reversal of 72804521 is 12540827.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42719296 + 30085225 = 6536^2 + 5485^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72804521 is a prime.

It is a super-3 number, since 3×72804521³ (a number of 25 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (72804527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36402260 + 36402261.

It is an arithmetic number, because the mean of its divisors is an integer number (36402261).

Almost surely, 2^72804521 is an apocalyptic number.

It is an amenable number.

72804521 is a deficient number, since it is larger than the sum of its proper divisors (1).

72804521 is an equidigital number, since it uses as much as digits as its factorization.

72804521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 72804521 is about 8532.5565336539. The cubic root of 72804521 is about 417.5605391074.

The spelling of 72804521 in words is "seventy-two million, eight hundred four thousand, five hundred twenty-one".