72866521 has 8 divisors (see below), whose sum is σ = 89681984. Its totient is φ = 57652560.

The previous prime is 72866503. The next prime is 72866527. The reversal of 72866521 is 12566827.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 72866521 - 2⁵ = 72866489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72866527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 400275 + ... + 400456.

It is an arithmetic number, because the mean of its divisors is an integer number (11210248).

Almost surely, 2^72866521 is an apocalyptic number.

It is an amenable number.

72866521 is a deficient number, since it is larger than the sum of its proper divisors (16815463).

72866521 is a wasteful number, since it uses less digits than its factorization.

72866521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800751.

The product of its digits is 40320, while the sum is 37.

The square root of 72866521 is about 8536.1889037204. The cubic root of 72866521 is about 417.6790363639.

It can be divided in two parts, 7286652 and 1, that added together give a triangular number (7286653 = T₃₈₁₇).

The spelling of 72866521 in words is "seventy-two million, eight hundred sixty-six thousand, five hundred twenty-one".