87139879 has 2 divisors, whose sum is σ = 87139880. Its totient is φ = 87139878.

The previous prime is 87139861. The next prime is 87139919. The reversal of 87139879 is 97893178.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87139879 - 2¹⁷ = 87008807 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87139859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43569939 + 43569940.

It is an arithmetic number, because the mean of its divisors is an integer number (43569940).

Almost surely, 2^87139879 is an apocalyptic number.

87139879 is a deficient number, since it is larger than the sum of its proper divisors (1).

87139879 is an equidigital number, since it uses as much as digits as its factorization.

87139879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 52.

The square root of 87139879 is about 9334.8743430214. The cubic root of 87139879 is about 443.3421103029.

The spelling of 87139879 in words is "eighty-seven million, one hundred thirty-nine thousand, eight hundred seventy-nine".