64561000780 has 24 divisors (see below), whose sum is σ = 135583006608. Its totient is φ = 25823466048.

The previous prime is 64561000747. The next prime is 64561000807. The reversal of 64561000780 is 8700016546.

64561000780 is a nontrivial binomial coefficient, being equal to C(359336, 2).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 862407 + ... + 934273.

It is an arithmetic number, because the mean of its divisors is an integer number (5649291942).

Almost surely, 2^64561000780 is an apocalyptic number.

64561000780 is the 359335-th triangular number and also the 179668-th hexagonal number.

64561000780 is the 119779-th centered nonagonal number.

It is an amenable number.

64561000780 is an abundant number, since it is smaller than the sum of its proper divisors (71022005828).

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

64561000780 is a wasteful number, since it uses less digits than its factorization.

64561000780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116793 (or 116791 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The spelling of 64561000780 in words is "sixty-four billion, five hundred sixty-one million, seven hundred eighty", and thus it is an aban number.