61879681864 has 64 divisors (see below), whose sum is σ = 155781037440. Its totient is φ = 22254428160.

The previous prime is 61879681861. The next prime is 61879681891. The reversal of 61879681864 is 46818697816.

It is a junction number, because it is equal to n+sod(n) for n = 61879681796 and 61879681805.

It is not an unprimeable number, because it can be changed into a prime (61879681861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3855609 + ... + 3871624.

It is an arithmetic number, because the mean of its divisors is an integer number (2434078710).

Almost surely, 2^61879681864 is an apocalyptic number.

It is an amenable number.

61879681864 is an abundant number, since it is smaller than the sum of its proper divisors (93901355576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61879681864 is a wasteful number, since it uses less digits than its factorization.

61879681864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7727270 (or 7727266 counting only the distinct ones).

The product of its digits is 27869184, while the sum is 64.

The spelling of 61879681864 in words is "sixty-one billion, eight hundred seventy-nine million, six hundred eighty-one thousand, eight hundred sixty-four".