65131981691 has 16 divisors (see below), whose sum is σ = 75457252800. Its totient is φ = 55064959488.

The previous prime is 65131981657. The next prime is 65131981699. The reversal of 65131981691 is 19618913156.

It is not a de Polignac number, because 65131981691 - 2¹⁴ = 65131965307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65131981699) 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, 127001 + ... + 382613.

It is an arithmetic number, because the mean of its divisors is an integer number (4716078300).

Almost surely, 2^65131981691 is an apocalyptic number.

65131981691 is a deficient number, since it is larger than the sum of its proper divisors (10325271109).

65131981691 is a wasteful number, since it uses less digits than its factorization.

65131981691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256118.

The product of its digits is 349920, while the sum is 50.

The spelling of 65131981691 in words is "sixty-five billion, one hundred thirty-one million, nine hundred eighty-one thousand, six hundred ninety-one".