1561655466641 has 48 divisors (see below), whose sum is σ = 1739995193664. Its totient is φ = 1396600415232.

The previous prime is 1561655466571. The next prime is 1561655466661. The reversal of 1561655466641 is 1466645561651.

It is a de Polignac number, because none of the positive numbers 2^k-1561655466641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561655466661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1649054930 + ... + 1649055876.

It is an arithmetic number, because the mean of its divisors is an integer number (36249899868).

Almost surely, 2^{1561655466641} is an apocalyptic number.

It is an amenable number.

1561655466641 is a deficient number, since it is larger than the sum of its proper divisors (178339727023).

1561655466641 is a wasteful number, since it uses less digits than its factorization.

1561655466641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2030 (or 2007 counting only the distinct ones).

The product of its digits is 15552000, while the sum is 56.

The spelling of 1561655466641 in words is "one trillion, five hundred sixty-one billion, six hundred fifty-five million, four hundred sixty-six thousand, six hundred forty-one".