87989809 has 2 divisors, whose sum is σ = 87989810. Its totient is φ = 87989808.

The previous prime is 87989723. The next prime is 87989819. The reversal of 87989809 is 90898978.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 85655025 + 2334784 = 9255^2 + 1528^2 .

It is a cyclic number.

It is not a de Polignac number, because 87989809 - 2¹⁵ = 87957041 is a prime.

It is not a weakly prime, because it can be changed into another prime (87989819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43994904 + 43994905.

It is an arithmetic number, because the mean of its divisors is an integer number (43994905).

Almost surely, 2^87989809 is an apocalyptic number.

It is an amenable number.

87989809 is a deficient number, since it is larger than the sum of its proper divisors (1).

87989809 is an equidigital number, since it uses as much as digits as its factorization.

87989809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2612736, while the sum is 58.

The square root of 87989809 is about 9380.2883217948. The cubic root of 87989809 is about 444.7788473138.

The spelling of 87989809 in words is "eighty-seven million, nine hundred eighty-nine thousand, eight hundred nine".