87090391 has 2 divisors, whose sum is σ = 87090392. Its totient is φ = 87090390.

The previous prime is 87090379. The next prime is 87090463. The reversal of 87090391 is 19309078.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87090391 - 2⁵ = 87090359 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 87090391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87090691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43545195 + 43545196.

It is an arithmetic number, because the mean of its divisors is an integer number (43545196).

Almost surely, 2^87090391 is an apocalyptic number.

87090391 is a deficient number, since it is larger than the sum of its proper divisors (1).

87090391 is an equidigital number, since it uses as much as digits as its factorization.

87090391 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 37.

The square root of 87090391 is about 9332.2232613670. The cubic root of 87090391 is about 443.2581676072.

The spelling of 87090391 in words is "eighty-seven million, ninety thousand, three hundred ninety-one".