15079721 has 4 divisors (see below), whose sum is σ = 15101700. Its totient is φ = 15057744.

The previous prime is 15079709. The next prime is 15079723. The reversal of 15079721 is 12797051.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12797051 = 19 ⋅673529.

It can be written as a sum of positive squares in 2 ways, for example, as 5125696 + 9954025 = 2264^2 + 3155^2 .

It is a cyclic number.

It is not a de Polignac number, because 15079721 - 2⁶ = 15079657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15079723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9926 + ... + 11343.

It is an arithmetic number, because the mean of its divisors is an integer number (3775425).

Almost surely, 2^15079721 is an apocalyptic number.

It is an amenable number.

15079721 is a deficient number, since it is larger than the sum of its proper divisors (21979).

15079721 is an equidigital number, since it uses as much as digits as its factorization.

15079721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21978.

The product of its (nonzero) digits is 4410, while the sum is 32.

The square root of 15079721 is about 3883.2616445457. The cubic root of 15079721 is about 247.0573443433.

The spelling of 15079721 in words is "fifteen million, seventy-nine thousand, seven hundred twenty-one".