15945545649 has 24 divisors (see below), whose sum is σ = 23912723296. Its totient is φ = 9439214400.

The previous prime is 15945545633. The next prime is 15945545657. The reversal of 15945545649 is 94654554951.

It is not a de Polignac number, because 15945545649 - 2⁴ = 15945545633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15945545659) 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, 495172 + ... + 526389.

Almost surely, 2^15945545649 is an apocalyptic number.

It is an amenable number.

15945545649 is a deficient number, since it is larger than the sum of its proper divisors (7967177647).

15945545649 is a wasteful number, since it uses less digits than its factorization.

15945545649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1021629 (or 1021618 counting only the distinct ones).

The product of its digits is 19440000, while the sum is 57.

The spelling of 15945545649 in words is "fifteen billion, nine hundred forty-five million, five hundred forty-five thousand, six hundred forty-nine".