87040813 has 2 divisors, whose sum is σ = 87040814. Its totient is φ = 87040812.

The previous prime is 87040739. The next prime is 87040819. The reversal of 87040813 is 31804078.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71690089 + 15350724 = 8467^2 + 3918^2 .

It is a cyclic number.

It is not a de Polignac number, because 87040813 - 2⁹ = 87040301 is a prime.

It is a super-2 number, since 2×87040813² = 15152206255401938, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87040819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43520406 + 43520407.

It is an arithmetic number, because the mean of its divisors is an integer number (43520407).

Almost surely, 2^87040813 is an apocalyptic number.

It is an amenable number.

87040813 is a deficient number, since it is larger than the sum of its proper divisors (1).

87040813 is an equidigital number, since it uses as much as digits as its factorization.

87040813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 87040813 is about 9329.5666030100. The cubic root of 87040813 is about 443.1740403590.

The spelling of 87040813 in words is "eighty-seven million, forty thousand, eight hundred thirteen".