61991866112 has 108 divisors (see below), whose sum is σ = 137060710248. Its totient is φ = 27961190400.

The previous prime is 61991866109. The next prime is 61991866141. The reversal of 61991866112 is 21166819916.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4050218 + ... + 4065494.

Almost surely, 2^61991866112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61991866112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68530355124).

61991866112 is an abundant number, since it is smaller than the sum of its proper divisors (75068844136).

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

61991866112 is a wasteful number, since it uses less digits than its factorization.

61991866112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15446 (or 15421 counting only the distinct ones).

The product of its digits is 279936, while the sum is 50.

The spelling of 61991866112 in words is "sixty-one billion, nine hundred ninety-one million, eight hundred sixty-six thousand, one hundred twelve".