1561566666660 has 192 divisors, whose sum is σ = 5870617288704. Its totient is φ = 299521267200.

The previous prime is 1561566666659. The next prime is 1561566666691. The reversal of 1561566666660 is 666666651651.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a junction number, because it is equal to n+sod(n) for n = 1561566666594 and 1561566666603.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12939996 + ... + 13060115.

It is an arithmetic number, because the mean of its divisors is an integer number (30576131712).

Almost surely, 2^{1561566666660} is an apocalyptic number.

1561566666660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1561566666660 is an abundant number, since it is smaller than the sum of its proper divisors (4309050622044).

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

1561566666660 is a wasteful number, since it uses less digits than its factorization.

1561566666660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26000154 (or 26000152 counting only the distinct ones).

The product of its (nonzero) digits is 41990400, while the sum is 60.

The spelling of 1561566666660 in words is "one trillion, five hundred sixty-one billion, five hundred sixty-six million, six hundred sixty-six thousand, six hundred sixty".