86691621 has 4 divisors (see below), whose sum is σ = 115588832. Its totient is φ = 57794412.

The previous prime is 86691601. The next prime is 86691637. The reversal of 86691621 is 12619668.

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 not a de Polignac number, because 86691621 - 2¹⁵ = 86658853 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 86691621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86691601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14448601 + ... + 14448606.

It is an arithmetic number, because the mean of its divisors is an integer number (28897208).

Almost surely, 2^86691621 is an apocalyptic number.

It is an amenable number.

86691621 is a deficient number, since it is larger than the sum of its proper divisors (28897211).

86691621 is a wasteful number, since it uses less digits than its factorization.

86691621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28897210.

The product of its digits is 31104, while the sum is 39.

The square root of 86691621 is about 9310.8335287449. The cubic root of 86691621 is about 442.5806013602.

The spelling of 86691621 in words is "eighty-six million, six hundred ninety-one thousand, six hundred twenty-one".