85990391 has 2 divisors, whose sum is σ = 85990392. Its totient is φ = 85990390.

The previous prime is 85990363. The next prime is 85990397. The reversal of 85990391 is 19309958.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85990391 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85990397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42995195 + 42995196.

It is an arithmetic number, because the mean of its divisors is an integer number (42995196).

Almost surely, 2^85990391 is an apocalyptic number.

85990391 is a deficient number, since it is larger than the sum of its proper divisors (1).

85990391 is an equidigital number, since it uses as much as digits as its factorization.

85990391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 87480, while the sum is 44.

The square root of 85990391 is about 9273.1003984644. The cubic root of 85990391 is about 441.3840560297.

The spelling of 85990391 in words is "eighty-five million, nine hundred ninety thousand, three hundred ninety-one".