85991961 has 16 divisors (see below), whose sum is σ = 125614080. Its totient is φ = 51893520.

The previous prime is 85991957. The next prime is 85991977. The reversal of 85991961 is 16919958.

It is not a de Polignac number, because 85991961 - 2² = 85991957 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 85991961.

It is not an unprimeable number, because it can be changed into a prime (85991981) 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, 2436 + ... + 13338.

It is an arithmetic number, because the mean of its divisors is an integer number (7850880).

Almost surely, 2^85991961 is an apocalyptic number.

It is an amenable number.

85991961 is a deficient number, since it is larger than the sum of its proper divisors (39622119).

85991961 is a wasteful number, since it uses less digits than its factorization.

85991961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11156.

The product of its digits is 174960, while the sum is 48.

The square root of 85991961 is about 9273.1850515343. The cubic root of 85991961 is about 441.3867422552.

The spelling of 85991961 in words is "eighty-five million, nine hundred ninety-one thousand, nine hundred sixty-one".