87139139 has 2 divisors, whose sum is σ = 87139140. Its totient is φ = 87139138.

The previous prime is 87139123. The next prime is 87139153. The reversal of 87139139 is 93193178.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 87139139 - 2⁴ = 87139123 is a prime.

It is a super-2 number, since 2×87139139² = 15186459091322642, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 87139096 and 87139105.

It is not a weakly prime, because it can be changed into another prime (87139439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43569569 + 43569570.

It is an arithmetic number, because the mean of its divisors is an integer number (43569570).

Almost surely, 2^87139139 is an apocalyptic number.

87139139 is a deficient number, since it is larger than the sum of its proper divisors (1).

87139139 is an equidigital number, since it uses as much as digits as its factorization.

87139139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 41.

The square root of 87139139 is about 9334.8347066244. The cubic root of 87139139 is about 443.3408553318.

It can be divided in two parts, 87139 and 139, that added together give a palindrome (87278).

The spelling of 87139139 in words is "eighty-seven million, one hundred thirty-nine thousand, one hundred thirty-nine".