15975997 has 4 divisors (see below), whose sum is σ = 16140796. Its totient is φ = 15811200.

The previous prime is 15975991. The next prime is 15976001. The reversal of 15975997 is 79957951.

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: 79957951 = 47 ⋅1701233.

It can be written as a sum of positive squares in 2 ways, for example, as 12538681 + 3437316 = 3541^2 + 1854^2 .

It is a cyclic number.

It is not a de Polignac number, because 15975997 - 2¹¹ = 15973949 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 (15975991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82254 + ... + 82447.

It is an arithmetic number, because the mean of its divisors is an integer number (4035199).

Almost surely, 2^15975997 is an apocalyptic number.

It is an amenable number.

15975997 is a deficient number, since it is larger than the sum of its proper divisors (164799).

15975997 is an equidigital number, since it uses as much as digits as its factorization.

15975997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164798.

The product of its digits is 893025, while the sum is 52.

The square root of 15975997 is about 3996.9984988739. The cubic root of 15975997 is about 251.8581390606.

The spelling of 15975997 in words is "fifteen million, nine hundred seventy-five thousand, nine hundred ninety-seven".