85658991 has 16 divisors (see below), whose sum is σ = 124771968. Its totient is φ = 51840800.

The previous prime is 85658987. The next prime is 85658999. The reversal of 85658991 is 19985658.

It is not a de Polignac number, because 85658991 - 2² = 85658987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85658999) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29881 + ... + 32621.

It is an arithmetic number, because the mean of its divisors is an integer number (7798248).

Almost surely, 2^85658991 is an apocalyptic number.

85658991 is a deficient number, since it is larger than the sum of its proper divisors (39112977).

85658991 is a wasteful number, since it uses less digits than its factorization.

85658991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3702.

The product of its digits is 777600, while the sum is 51.

The square root of 85658991 is about 9255.2142600806. The cubic root of 85658991 is about 440.8163065867.

The spelling of 85658991 in words is "eighty-five million, six hundred fifty-eight thousand, nine hundred ninety-one".