65981683161 has 15 divisors (see below), whose sum is σ = 98568683983. Its totient is φ = 43986247560.

The previous prime is 65981683127. The next prime is 65981683181. The reversal of 65981683161 is 16138618956.

The square root of 65981683161 is 256869.

It is a perfect power (a square), and thus also a powerful number.

65981683161 is a `hidden beast` number, since 6 + 598 + 16 + 8 + 31 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16083058761 + 49898624400 = 126819^2 + 223380^2 .

It is not a de Polignac number, because 65981683161 - 2³⁵ = 31621944793 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 65981683098 and 65981683107.

It is not an unprimeable number, because it can be changed into a prime (65981683181) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 2297551 + ... + 2326091.

Almost surely, 2^65981683161 is an apocalyptic number.

65981683161 is the 256869-th square number.

65981683161 is the 128435-th centered octagonal number.

It is an amenable number.

65981683161 is a deficient number, since it is larger than the sum of its proper divisors (32587000822).

65981683161 is an frugal number, since it uses more digits than its factorization.

65981683161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57094 (or 28544 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The spelling of 65981683161 in words is "sixty-five billion, nine hundred eighty-one million, six hundred eighty-three thousand, one hundred sixty-one".