1661566000655 has 16 divisors (see below), whose sum is σ = 2177954897184. Its totient is φ = 1206848330880.

The previous prime is 1661566000609. The next prime is 1661566000663. The reversal of 1661566000655 is 5560006651661.

It is not a de Polignac number, because 1661566000655 - 2¹⁶ = 1661565935119 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19498424 + ... + 19583453.

It is an arithmetic number, because the mean of its divisors is an integer number (136122181074).

Almost surely, 2^{1661566000655} is an apocalyptic number.

1661566000655 is a deficient number, since it is larger than the sum of its proper divisors (516388896529).

1661566000655 is a wasteful number, since it uses less digits than its factorization.

1661566000655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39082666.

The product of its (nonzero) digits is 972000, while the sum is 47.

The spelling of 1661566000655 in words is "one trillion, six hundred sixty-one billion, five hundred sixty-six million, six hundred fifty-five", and thus it is an aban number.