86579721 has 12 divisors (see below), whose sum is σ = 125752900. Its totient is φ = 57399840.

The previous prime is 86579693. The next prime is 86579723. The reversal of 86579721 is 12797568.

86579721 is a `hidden beast` number, since 8 + 6 + 579 + 72 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20385225 + 66194496 = 4515^2 + 8136^2 .

It is not a de Polignac number, because 86579721 - 2¹⁰ = 86578697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (86579723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24946 + ... + 28203.

Almost surely, 2^86579721 is an apocalyptic number.

It is an amenable number.

86579721 is a deficient number, since it is larger than the sum of its proper divisors (39173179).

86579721 is a wasteful number, since it uses less digits than its factorization.

86579721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53336 (or 53333 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 86579721 is about 9304.8224593487. The cubic root of 86579721 is about 442.3900943171.

The spelling of 86579721 in words is "eighty-six million, five hundred seventy-nine thousand, seven hundred twenty-one".