15645099979 has 4 divisors (see below), whose sum is σ = 15750100800. Its totient is φ = 15540099160.

The previous prime is 15645099959. The next prime is 15645100073. The reversal of 15645099979 is 97999054651.

15645099979 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97999054651 = 53 ⋅1849038767.

It is a cyclic number.

It is not a de Polignac number, because 15645099979 - 2¹⁷ = 15644968907 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15645099979.

It is not an unprimeable number, because it can be changed into a prime (15645099929) 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 3 ways as a sum of consecutive naturals, for example, 52500187 + ... + 52500484.

It is an arithmetic number, because the mean of its divisors is an integer number (3937525200).

Almost surely, 2^15645099979 is an apocalyptic number.

15645099979 is a deficient number, since it is larger than the sum of its proper divisors (105000821).

15645099979 is a wasteful number, since it uses less digits than its factorization.

15645099979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105000820.

The product of its (nonzero) digits is 27556200, while the sum is 64.

The spelling of 15645099979 in words is "fifteen billion, six hundred forty-five million, ninety-nine thousand, nine hundred seventy-nine".