61678642689 has 6 divisors (see below), whose sum is σ = 89091372786. Its totient is φ = 41119095120.

The previous prime is 61678642687. The next prime is 61678642733. The reversal of 61678642689 is 98624687616.

61678642689 is a `hidden beast` number, since 61 + 6 + 78 + 6 + 426 + 89 = 666.

It can be written as a sum of positive squares in only one way, i.e., 40539809025 + 21138833664 = 201345^2 + 145392^2 .

It is not a de Polignac number, because 61678642689 - 2¹ = 61678642687 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61678642687) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3426591252 + ... + 3426591269.

It is an arithmetic number, because the mean of its divisors is an integer number (14848562131).

Almost surely, 2^61678642689 is an apocalyptic number.

It is an amenable number.

61678642689 is a deficient number, since it is larger than the sum of its proper divisors (27412730097).

61678642689 is a wasteful number, since it uses less digits than its factorization.

61678642689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6853182527 (or 6853182524 counting only the distinct ones).

The product of its digits is 41803776, while the sum is 63.

The spelling of 61678642689 in words is "sixty-one billion, six hundred seventy-eight million, six hundred forty-two thousand, six hundred eighty-nine".