87915881 has 2 divisors, whose sum is σ = 87915882. Its totient is φ = 87915880.

The previous prime is 87915833. The next prime is 87915941. The reversal of 87915881 is 18851978.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64722025 + 23193856 = 8045^2 + 4816^2 .

It is a cyclic number.

It is not a de Polignac number, because 87915881 - 2²² = 83721577 is a prime.

It is a super-2 number, since 2×87915881² = 15458404264012322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (87918881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43957940 + 43957941.

It is an arithmetic number, because the mean of its divisors is an integer number (43957941).

Almost surely, 2^87915881 is an apocalyptic number.

It is an amenable number.

87915881 is a deficient number, since it is larger than the sum of its proper divisors (1).

87915881 is an equidigital number, since it uses as much as digits as its factorization.

87915881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 161280, while the sum is 47.

The square root of 87915881 is about 9376.3468899140. The cubic root of 87915881 is about 444.6542464302.

The spelling of 87915881 in words is "eighty-seven million, nine hundred fifteen thousand, eight hundred eighty-one".