86991977 has 2 divisors, whose sum is σ = 86991978. Its totient is φ = 86991976.

The previous prime is 86991913. The next prime is 86992001. The reversal of 86991977 is 77919968.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 82373776 + 4618201 = 9076^2 + 2149^2 .

It is a cyclic number.

It is not a de Polignac number, because 86991977 - 2⁶ = 86991913 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (86991577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43495988 + 43495989.

It is an arithmetic number, because the mean of its divisors is an integer number (43495989).

Almost surely, 2^86991977 is an apocalyptic number.

It is an amenable number.

86991977 is a deficient number, since it is larger than the sum of its proper divisors (1).

86991977 is an equidigital number, since it uses as much as digits as its factorization.

86991977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1714608, while the sum is 56.

The square root of 86991977 is about 9326.9489652297. The cubic root of 86991977 is about 443.0911409479.

The spelling of 86991977 in words is "eighty-six million, nine hundred ninety-one thousand, nine hundred seventy-seven".