61561646559 has 48 divisors (see below), whose sum is σ = 113266932480. Its totient is φ = 31366206720.

The previous prime is 61561646551. The next prime is 61561646561. The reversal of 61561646559 is 95564616516.

61561646559 is a `hidden beast` number, since 6 + 15 + 616 + 4 + 6 + 5 + 5 + 9 = 666.

It is not a de Polignac number, because 61561646559 - 2³ = 61561646551 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61561646551) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1492297 + ... + 1532994.

It is an arithmetic number, because the mean of its divisors is an integer number (2359727760).

Almost surely, 2^61561646559 is an apocalyptic number.

61561646559 is a deficient number, since it is larger than the sum of its proper divisors (51705285921).

61561646559 is a wasteful number, since it uses less digits than its factorization.

61561646559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3025340 (or 3025337 counting only the distinct ones).

The product of its digits is 5832000, while the sum is 54.

The spelling of 61561646559 in words is "sixty-one billion, five hundred sixty-one million, six hundred forty-six thousand, five hundred fifty-nine".