1561500864000 has 3840 divisors, whose sum is σ = 7886966630400. Its totient is φ = 286654464000.

The previous prime is 1561500863987. The next prime is 1561500864023. The reversal of 1561500864000 is 4680051651.

1561500864000 is a `hidden beast` number, since 1 + 5 + 6 + 1 + 5 + 0 + 0 + 8 + 640 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3840).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 14325695946 + ... + 14325696054.

It is an arithmetic number, because the mean of its divisors is an integer number (2053897560).

Almost surely, 2^{1561500864000} is an apocalyptic number.

1561500864000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561500864000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3943483315200).

1561500864000 is an abundant number, since it is smaller than the sum of its proper divisors (6325465766400).

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

1561500864000 is a wasteful number, since it uses less digits than its factorization.

1561500864000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The spelling of 1561500864000 in words is "one trillion, five hundred sixty-one billion, five hundred million, eight hundred sixty-four thousand".