85511391 has 32 divisors (see below), whose sum is σ = 134204928. Its totient is φ = 47416320.

The previous prime is 85511383. The next prime is 85511399. The reversal of 85511391 is 19311558.

It is an interprime number because it is at equal distance from previous prime (85511383) and next prime (85511399).

It is not a de Polignac number, because 85511391 - 2³ = 85511383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85511399) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 253575 + ... + 253911.

It is an arithmetic number, because the mean of its divisors is an integer number (4193904).

Almost surely, 2^85511391 is an apocalyptic number.

85511391 is a deficient number, since it is larger than the sum of its proper divisors (48693537).

85511391 is a wasteful number, since it uses less digits than its factorization.

85511391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671.

The product of its digits is 5400, while the sum is 33.

The square root of 85511391 is about 9247.2369386752. The cubic root of 85511391 is about 440.5629691260.

It can be divided in two parts, 855 and 11391, that added together give a triangular number (12246 = T₁₅₆).

The spelling of 85511391 in words is "eighty-five million, five hundred eleven thousand, three hundred ninety-one".