15668961657 has 8 divisors (see below), whose sum is σ = 20906333184. Its totient is φ = 10438782288.

The previous prime is 15668961647. The next prime is 15668961689. The reversal of 15668961657 is 75616986651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15668961657 - 2⁶ = 15668961593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15668961657.

It is not an unprimeable number, because it can be changed into a prime (15668961647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1792953 + ... + 1801670.

It is an arithmetic number, because the mean of its divisors is an integer number (2613291648).

Almost surely, 2^15668961657 is an apocalyptic number.

It is an amenable number.

15668961657 is a deficient number, since it is larger than the sum of its proper divisors (5237371527).

15668961657 is a wasteful number, since it uses less digits than its factorization.

15668961657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3596079.

The product of its digits is 16329600, while the sum is 60.

The spelling of 15668961657 in words is "fifteen billion, six hundred sixty-eight million, nine hundred sixty-one thousand, six hundred fifty-seven".