561601656651 has 24 divisors (see below), whose sum is σ = 916900668480. Its totient is φ = 304024955472.

The previous prime is 561601656647. The next prime is 561601656677. The reversal of 561601656651 is 156656106165.

It is not a de Polignac number, because 561601656651 - 2² = 561601656647 is a prime.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 561601656651.

It is not an unprimeable number, because it can be changed into a prime (561601656641) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 100534561 + ... + 100540146.

It is an arithmetic number, because the mean of its divisors is an integer number (38204194520).

Almost surely, 2^561601656651 is an apocalyptic number.

561601656651 is a deficient number, since it is larger than the sum of its proper divisors (355299011829).

561601656651 is a wasteful number, since it uses less digits than its factorization.

561601656651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201074743 (or 201074736 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 48.

The spelling of 561601656651 in words is "five hundred sixty-one billion, six hundred one million, six hundred fifty-six thousand, six hundred fifty-one".