87815899 has 2 divisors, whose sum is σ = 87815900. Its totient is φ = 87815898.

The previous prime is 87815873. The next prime is 87815977. The reversal of 87815899 is 99851878.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87815899 is a prime.

It is not a weakly prime, because it can be changed into another prime (87815699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43907949 + 43907950.

It is an arithmetic number, because the mean of its divisors is an integer number (43907950).

Almost surely, 2^87815899 is an apocalyptic number.

87815899 is a deficient number, since it is larger than the sum of its proper divisors (1).

87815899 is an equidigital number, since it uses as much as digits as its factorization.

87815899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1451520, while the sum is 55.

The square root of 87815899 is about 9371.0137658633. The cubic root of 87815899 is about 444.4856220436.

The spelling of 87815899 in words is "eighty-seven million, eight hundred fifteen thousand, eight hundred ninety-nine".