15991797 has 8 divisors (see below), whose sum is σ = 21776256. Its totient is φ = 10434272.

The previous prime is 15991793. The next prime is 15991817. The reversal of 15991797 is 79719951.

It is a happy number.

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 15991797 - 2² = 15991793 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15991793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56568 + ... + 56849.

It is an arithmetic number, because the mean of its divisors is an integer number (2722032).

Almost surely, 2^15991797 is an apocalyptic number.

It is an amenable number.

15991797 is a deficient number, since it is larger than the sum of its proper divisors (5784459).

15991797 is a wasteful number, since it uses less digits than its factorization.

15991797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113467.

The product of its digits is 178605, while the sum is 48.

The square root of 15991797 is about 3998.9744935421. The cubic root of 15991797 is about 251.9411395660.

The spelling of 15991797 in words is "fifteen million, nine hundred ninety-one thousand, seven hundred ninety-seven".