72966581 has 4 divisors (see below), whose sum is σ = 75482700. Its totient is φ = 70450464.

The previous prime is 72966577. The next prime is 72966583. The reversal of 72966581 is 18566927.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 27133681 + 45832900 = 5209^2 + 6770^2 .

It is a cyclic number.

It is not a de Polignac number, because 72966581 - 2² = 72966577 is a prime.

It is a super-2 number, since 2×72966581² = 10648243885659122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72966583) 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, 1258016 + ... + 1258073.

It is an arithmetic number, because the mean of its divisors is an integer number (18870675).

Almost surely, 2^72966581 is an apocalyptic number.

It is an amenable number.

72966581 is a deficient number, since it is larger than the sum of its proper divisors (2516119).

72966581 is a wasteful number, since it uses less digits than its factorization.

72966581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2516118.

The product of its digits is 181440, while the sum is 44.

The square root of 72966581 is about 8542.0478223901. The cubic root of 72966581 is about 417.8701339508.

The spelling of 72966581 in words is "seventy-two million, nine hundred sixty-six thousand, five hundred eighty-one".