15975121 has 4 divisors (see below), whose sum is σ = 16914852. Its totient is φ = 15035392.

The previous prime is 15975119. The next prime is 15975151. The reversal of 15975121 is 12157951.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14440000 + 1535121 = 3800^2 + 1239^2 .

It is a cyclic number.

It is not a de Polignac number, because 15975121 - 2¹ = 15975119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15975151) 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, 469840 + ... + 469873.

It is an arithmetic number, because the mean of its divisors is an integer number (4228713).

Almost surely, 2^15975121 is an apocalyptic number.

It is an amenable number.

15975121 is a deficient number, since it is larger than the sum of its proper divisors (939731).

15975121 is an equidigital number, since it uses as much as digits as its factorization.

15975121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 939730.

The product of its digits is 3150, while the sum is 31.

The square root of 15975121 is about 3996.8889151439. Note that the first 3 decimals coincide. The cubic root of 15975121 is about 251.8535356596.

The spelling of 15975121 in words is "fifteen million, nine hundred seventy-five thousand, one hundred twenty-one".