65819961 has 12 divisors (see below), whose sum is σ = 95311060. Its totient is φ = 43770240.

The previous prime is 65819959. The next prime is 65819969. The reversal of 65819961 is 16991856.

65819961 is a `hidden beast` number, since 6 + 581 + 9 + 9 + 61 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 44475561 + 21344400 = 6669^2 + 4620^2 .

It is not a de Polignac number, because 65819961 - 2¹ = 65819959 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65819969) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5260 + ... + 12621.

Almost surely, 2^65819961 is an apocalyptic number.

It is an amenable number.

65819961 is a deficient number, since it is larger than the sum of its proper divisors (29491099).

65819961 is a wasteful number, since it uses less digits than its factorization.

65819961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18296 (or 18293 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 65819961 is about 8112.9502032245. The cubic root of 65819961 is about 403.7562023668.

The spelling of 65819961 in words is "sixty-five million, eight hundred nineteen thousand, nine hundred sixty-one".