81974674161 has 8 divisors (see below), whose sum is σ = 121443961760. Its totient is φ = 54649782756.

The previous prime is 81974674151. The next prime is 81974674181. The reversal of 81974674161 is 16147647918.

81974674161 is a `hidden beast` number, since 8 + 19 + 7 + 467 + 4 + 161 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-81974674161 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81974674098 and 81974674107.

It is not an unprimeable number, because it can be changed into a prime (81974674151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1518049495 + ... + 1518049548.

It is an arithmetic number, because the mean of its divisors is an integer number (15180495220).

Almost surely, 2^81974674161 is an apocalyptic number.

It is an amenable number.

81974674161 is a deficient number, since it is larger than the sum of its proper divisors (39469287599).

81974674161 is a wasteful number, since it uses less digits than its factorization.

81974674161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3036099052 (or 3036099046 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 54.

The spelling of 81974674161 in words is "eighty-one billion, nine hundred seventy-four million, six hundred seventy-four thousand, one hundred sixty-one".