15997801 has 4 divisors (see below), whose sum is σ = 16430212. Its totient is φ = 15565392.

The previous prime is 15997789. The next prime is 15997819. The reversal of 15997801 is 10879951.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10879951 = 19 ⋅572629.

It can be written as a sum of positive squares in 2 ways, for example, as 13104400 + 2893401 = 3620^2 + 1701^2 .

It is a cyclic number.

It is not a de Polignac number, because 15997801 - 2⁵ = 15997769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15997841) 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 3 ways as a sum of consecutive naturals, for example, 216150 + ... + 216223.

It is an arithmetic number, because the mean of its divisors is an integer number (4107553).

Almost surely, 2^15997801 is an apocalyptic number.

It is an amenable number.

15997801 is a deficient number, since it is larger than the sum of its proper divisors (432411).

15997801 is an equidigital number, since it uses as much as digits as its factorization.

15997801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432410.

The product of its (nonzero) digits is 22680, while the sum is 40.

The square root of 15997801 is about 3999.7251155548. The cubic root of 15997801 is about 251.9726654235.

The spelling of 15997801 in words is "fifteen million, nine hundred ninety-seven thousand, eight hundred one".