15945558993 has 160 divisors (see below), whose sum is σ = 31623863040. Its totient is φ = 7771023360.

The previous prime is 15945558973. The next prime is 15945559009. The reversal of 15945558993 is 39985554951.

15945558993 is a `hidden beast` number, since 1 + 5 + 9 + 45 + 5 + 589 + 9 + 3 = 666.

It is not a de Polignac number, because 15945558993 - 2¹⁷ = 15945427921 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 15945558993.

It is not an unprimeable number, because it can be changed into a prime (15945558913) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 5740621 + ... + 5743397.

It is an arithmetic number, because the mean of its divisors is an integer number (197649144).

Almost surely, 2^15945558993 is an apocalyptic number.

15945558993 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

15945558993 is a deficient number, since it is larger than the sum of its proper divisors (15678304047).

15945558993 is a wasteful number, since it uses less digits than its factorization.

15945558993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2869 (or 2860 counting only the distinct ones).

The product of its digits is 43740000, while the sum is 63.

The spelling of 15945558993 in words is "fifteen billion, nine hundred forty-five million, five hundred fifty-eight thousand, nine hundred ninety-three".