87139859 has 2 divisors, whose sum is σ = 87139860. Its totient is φ = 87139858.

The previous prime is 87139831. The next prime is 87139861. The reversal of 87139859 is 95893178.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87139859 is a prime.

It is a Sophie Germain prime.

Together with 87139861, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87139879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43569929 + 43569930.

It is an arithmetic number, because the mean of its divisors is an integer number (43569930).

Almost surely, 2^87139859 is an apocalyptic number.

87139859 is a deficient number, since it is larger than the sum of its proper divisors (1).

87139859 is an equidigital number, since it uses as much as digits as its factorization.

87139859 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 50.

The square root of 87139859 is about 9334.8732717697. The cubic root of 87139859 is about 443.3420763849.

The spelling of 87139859 in words is "eighty-seven million, one hundred thirty-nine thousand, eight hundred fifty-nine".