15981170399 has 4 divisors (see below), whose sum is σ = 16921239264. Its totient is φ = 15041101536.

The previous prime is 15981170393. The next prime is 15981170407. The reversal of 15981170399 is 99307118951.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99307118951 = 727 ⋅136598513.

It is a cyclic number.

It is not a de Polignac number, because 15981170399 - 2⁸ = 15981170143 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 15981170399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15981170393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 470034407 + ... + 470034440.

It is an arithmetic number, because the mean of its divisors is an integer number (4230309816).

Almost surely, 2^15981170399 is an apocalyptic number.

15981170399 is a deficient number, since it is larger than the sum of its proper divisors (940068865).

15981170399 is an equidigital number, since it uses as much as digits as its factorization.

15981170399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 940068864.

The product of its (nonzero) digits is 612360, while the sum is 53.

The spelling of 15981170399 in words is "fifteen billion, nine hundred eighty-one million, one hundred seventy thousand, three hundred ninety-nine".