65809131 has 16 divisors (see below), whose sum is σ = 89819520. Its totient is φ = 42845760.

The previous prime is 65809129. The next prime is 65809151. The reversal of 65809131 is 13190856.

It is not a de Polignac number, because 65809131 - 2¹ = 65809129 is a prime.

It is a super-2 number, since 2×65809131² = 8661683445950322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 65809092 and 65809101.

It is not an unprimeable number, because it can be changed into a prime (65809111) 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, 27711 + ... + 29991.

It is an arithmetic number, because the mean of its divisors is an integer number (5613720).

Almost surely, 2^65809131 is an apocalyptic number.

65809131 is a deficient number, since it is larger than the sum of its proper divisors (24010389).

65809131 is a wasteful number, since it uses less digits than its factorization.

65809131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2506.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 65809131 is about 8112.2827243631. The cubic root of 65809131 is about 403.7340565038.

Adding to 65809131 its reverse (13190856), we get a palindrome (78999987).

The spelling of 65809131 in words is "sixty-five million, eight hundred nine thousand, one hundred thirty-one".