1561607681644 has 24 divisors (see below), whose sum is σ = 2740747690800. Its totient is φ = 778539789120.

The previous prime is 1561607681609. The next prime is 1561607681671. The reversal of 1561607681644 is 4461867061651.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1817739 + ... + 2535229.

It is an arithmetic number, because the mean of its divisors is an integer number (114197820450).

Almost surely, 2^{1561607681644} is an apocalyptic number.

It is an amenable number.

1561607681644 is a deficient number, since it is larger than the sum of its proper divisors (1179140009156).

1561607681644 is a wasteful number, since it uses less digits than its factorization.

1561607681644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719073 (or 719071 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 55.

The spelling of 1561607681644 in words is "one trillion, five hundred sixty-one billion, six hundred seven million, six hundred eighty-one thousand, six hundred forty-four".