1561655466643 has 16 divisors (see below), whose sum is σ = 1620599500800. Its totient is φ = 1503718931520.

The previous prime is 1561655466571. The next prime is 1561655466661. The reversal of 1561655466643 is 3466645561651.

It is a cyclic number.

It is not a de Polignac number, because 1561655466643 - 2²¹ = 1561653369491 is a prime.

It is a super-3 number, since 3×1561655466643³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561655466443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8718180 + ... + 8895502.

It is an arithmetic number, because the mean of its divisors is an integer number (101287468800).

Almost surely, 2^{1561655466643} is an apocalyptic number.

1561655466643 is a deficient number, since it is larger than the sum of its proper divisors (58944034157).

1561655466643 is a wasteful number, since it uses less digits than its factorization.

1561655466643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180162.

The product of its digits is 46656000, while the sum is 58.

The spelling of 1561655466643 in words is "one trillion, five hundred sixty-one billion, six hundred fifty-five million, four hundred sixty-six thousand, six hundred forty-three".