72819581 has 2 divisors, whose sum is σ = 72819582. Its totient is φ = 72819580.

The previous prime is 72819577. The next prime is 72819611. The reversal of 72819581 is 18591827.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72097081 + 722500 = 8491^2 + 850^2 .

It is a cyclic number.

It is not a de Polignac number, because 72819581 - 2² = 72819577 is a prime.

It is a super-2 number, since 2×72819581² = 10605382754031122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72810581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36409790 + 36409791.

It is an arithmetic number, because the mean of its divisors is an integer number (36409791).

Almost surely, 2^72819581 is an apocalyptic number.

It is an amenable number.

72819581 is a deficient number, since it is larger than the sum of its proper divisors (1).

72819581 is an equidigital number, since it uses as much as digits as its factorization.

72819581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 41.

The square root of 72819581 is about 8533.4389902313. The cubic root of 72819581 is about 417.5893286573.

The spelling of 72819581 in words is "seventy-two million, eight hundred nineteen thousand, five hundred eighty-one".