65813891 has 16 divisors (see below), whose sum is σ = 81392640. Its totient is φ = 52319520.

The previous prime is 65813887. The next prime is 65813893. The reversal of 65813891 is 19831856.

It is not a de Polignac number, because 65813891 - 2² = 65813887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65813893) 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, 9395 + ... + 14828.

It is an arithmetic number, because the mean of its divisors is an integer number (5087040).

Almost surely, 2^65813891 is an apocalyptic number.

65813891 is a deficient number, since it is larger than the sum of its proper divisors (15578749).

65813891 is a wasteful number, since it uses less digits than its factorization.

65813891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24266.

The product of its digits is 51840, while the sum is 41.

The square root of 65813891 is about 8112.5761013380. The cubic root of 65813891 is about 403.7437903495.

The spelling of 65813891 in words is "sixty-five million, eight hundred thirteen thousand, eight hundred ninety-one".