15653561661 has 16 divisors (see below), whose sum is σ = 23192433600. Its totient is φ = 10434820464.

The previous prime is 15653561639. The next prime is 15653561663. The reversal of 15653561661 is 16616535651.

15653561661 is a `hidden beast` number, since 1 + 56 + 535 + 6 + 1 + 6 + 61 = 666.

15653561661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 15653561661 - 2⁷ = 15653561533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15653561663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 508275 + ... + 538191.

It is an arithmetic number, because the mean of its divisors is an integer number (1449527100).

Almost surely, 2^15653561661 is an apocalyptic number.

It is an amenable number.

15653561661 is a deficient number, since it is larger than the sum of its proper divisors (7538871939).

15653561661 is a wasteful number, since it uses less digits than its factorization.

15653561661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49305 (or 49299 counting only the distinct ones).

The product of its digits is 486000, while the sum is 45.

The spelling of 15653561661 in words is "fifteen billion, six hundred fifty-three million, five hundred sixty-one thousand, six hundred sixty-one".