86621561 has 8 divisors (see below), whose sum is σ = 95560584. Its totient is φ = 78007680.

The previous prime is 86621531. The next prime is 86621567. The reversal of 86621561 is 16512668.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1336336 + 85285225 = 1156^2 + 9235^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 86621561 - 2²⁶ = 19512697 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 (86621567) 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, 80726 + ... + 81791.

It is an arithmetic number, because the mean of its divisors is an integer number (11945073).

Almost surely, 2^86621561 is an apocalyptic number.

It is an amenable number.

86621561 is a deficient number, since it is larger than the sum of its proper divisors (8939023).

86621561 is a wasteful number, since it uses less digits than its factorization.

86621561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162571.

The product of its digits is 17280, while the sum is 35.

The square root of 86621561 is about 9307.0704843146. The cubic root of 86621561 is about 442.4613451077.

The spelling of 86621561 in words is "eighty-six million, six hundred twenty-one thousand, five hundred sixty-one".