87109391 has 2 divisors, whose sum is σ = 87109392. Its totient is φ = 87109390.

The previous prime is 87109339. The next prime is 87109397. The reversal of 87109391 is 19390178.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 87109391 - 2²² = 82915087 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87109397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43554695 + 43554696.

It is an arithmetic number, because the mean of its divisors is an integer number (43554696).

Almost surely, 2^87109391 is an apocalyptic number.

87109391 is a deficient number, since it is larger than the sum of its proper divisors (1).

87109391 is an equidigital number, since it uses as much as digits as its factorization.

87109391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 38.

The square root of 87109391 is about 9333.2411840689. The cubic root of 87109391 is about 443.2903996086.

The spelling of 87109391 in words is "eighty-seven million, one hundred nine thousand, three hundred ninety-one".