1561982745600 has 660 divisors, whose sum is σ = 5799816995544. Its totient is φ = 415379128320.

The previous prime is 1561982745551. The next prime is 1561982745679. The reversal of 1561982745600 is 65472891651.

It is a happy number.

1561982745600 is a `hidden beast` number, since 1 + 5 + 6 + 1 + 9 + 8 + 2 + 74 + 560 + 0 = 666.

It is a super-2 number, since 2×1561982745600² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 968370394 + ... + 968372006.

Almost surely, 2^{1561982745600} is an apocalyptic number.

1561982745600 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 1561982745600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2899908497772).

1561982745600 is an abundant number, since it is smaller than the sum of its proper divisors (4237834249944).

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

1561982745600 is a wasteful number, since it uses less digits than its factorization.

1561982745600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2122 (or 2090 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 1561982745600 in words is "one trillion, five hundred sixty-one billion, nine hundred eighty-two million, seven hundred forty-five thousand, six hundred".