72766581 has 4 divisors (see below), whose sum is σ = 97022112. Its totient is φ = 48511052.

The previous prime is 72766571. The next prime is 72766583. The reversal of 72766581 is 18566727.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72766581 - 2⁷ = 72766453 is a prime.

It is a super-2 number, since 2×72766581² = 10589950620859122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72766583) 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 in 3 ways as a sum of consecutive naturals, for example, 12127761 + ... + 12127766.

It is an arithmetic number, because the mean of its divisors is an integer number (24255528).

Almost surely, 2^72766581 is an apocalyptic number.

It is an amenable number.

72766581 is a deficient number, since it is larger than the sum of its proper divisors (24255531).

72766581 is a wasteful number, since it uses less digits than its factorization.

72766581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24255530.

The product of its digits is 141120, while the sum is 42.

The square root of 72766581 is about 8530.3329946726. The cubic root of 72766581 is about 417.4879932484.

The spelling of 72766581 in words is "seventy-two million, seven hundred sixty-six thousand, five hundred eighty-one".