15991849 has 8 divisors (see below), whose sum is σ = 17253000. Its totient is φ = 14766336.

The previous prime is 15991837. The next prime is 15991897. The reversal of 15991849 is 94819951.

It can be written as a sum of positive squares in 4 ways, for example, as 2250000 + 13741849 = 1500^2 + 3707^2 .

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

It is not a de Polignac number, because 15991849 - 2⁵ = 15991817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15991799 and 15991808.

It is not an unprimeable number, because it can be changed into a prime (15991649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7974 + ... + 9775.

It is an arithmetic number, because the mean of its divisors is an integer number (2156625).

Almost surely, 2^15991849 is an apocalyptic number.

It is an amenable number.

15991849 is a deficient number, since it is larger than the sum of its proper divisors (1261151).

15991849 is a wasteful number, since it uses less digits than its factorization.

15991849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17819.

The product of its digits is 116640, while the sum is 46.

The square root of 15991849 is about 3998.9809952037. The cubic root of 15991849 is about 251.9414126420.

The spelling of 15991849 in words is "fifteen million, nine hundred ninety-one thousand, eight hundred forty-nine".