87990137 has 2 divisors, whose sum is σ = 87990138. Its totient is φ = 87990136.

The previous prime is 87990101. The next prime is 87990143. The reversal of 87990137 is 73109978.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84345856 + 3644281 = 9184^2 + 1909^2 .

It is a cyclic number.

It is not a de Polignac number, because 87990137 - 2¹⁰ = 87989113 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87990937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43995068 + 43995069.

It is an arithmetic number, because the mean of its divisors is an integer number (43995069).

Almost surely, 2^87990137 is an apocalyptic number.

It is an amenable number.

87990137 is a deficient number, since it is larger than the sum of its proper divisors (1).

87990137 is an equidigital number, since it uses as much as digits as its factorization.

87990137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 95256, while the sum is 44.

The square root of 87990137 is about 9380.3058052496. The cubic root of 87990137 is about 444.7793999812.

The spelling of 87990137 in words is "eighty-seven million, nine hundred ninety thousand, one hundred thirty-seven".