15945949657 has 16 divisors (see below), whose sum is σ = 18777847680. Its totient is φ = 13387897600.

The previous prime is 15945949651. The next prime is 15945949661. The reversal of 15945949657 is 75694954951.

It is a de Polignac number, because none of the positive numbers 2^k-15945949657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15945949651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1079344 + ... + 1094017.

It is an arithmetic number, because the mean of its divisors is an integer number (1173615480).

Almost surely, 2^15945949657 is an apocalyptic number.

It is an amenable number.

15945949657 is a deficient number, since it is larger than the sum of its proper divisors (2831898023).

15945949657 is a wasteful number, since it uses less digits than its factorization.

15945949657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2173424.

The product of its digits is 61236000, while the sum is 64.

The spelling of 15945949657 in words is "fifteen billion, nine hundred forty-five million, nine hundred forty-nine thousand, six hundred fifty-seven".