15991191397 has 8 divisors (see below), whose sum is σ = 16548940800. Its totient is φ = 15433863984.

The previous prime is 15991191383. The next prime is 15991191401. The reversal of 15991191397 is 79319119951.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 15991191397 - 2²³ = 15982802789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15991191317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27397 + ... + 180922.

It is an arithmetic number, because the mean of its divisors is an integer number (2068617600).

Almost surely, 2^15991191397 is an apocalyptic number.

It is an amenable number.

15991191397 is a deficient number, since it is larger than the sum of its proper divisors (557749403).

15991191397 is a wasteful number, since it uses less digits than its factorization.

15991191397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210995.

The product of its digits is 688905, while the sum is 55.

The spelling of 15991191397 in words is "fifteen billion, nine hundred ninety-one million, one hundred ninety-one thousand, three hundred ninety-seven".