15680121 has 4 divisors (see below), whose sum is σ = 20906832. Its totient is φ = 10453412.

The previous prime is 15680117. The next prime is 15680143. The reversal of 15680121 is 12108651.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12108651 = 3 ⋅4036217.

It is a cyclic number.

It is not a de Polignac number, because 15680121 - 2² = 15680117 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 15680091 and 15680100.

It is not an unprimeable number, because it can be changed into a prime (15680321) 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, 2613351 + ... + 2613356.

It is an arithmetic number, because the mean of its divisors is an integer number (5226708).

Almost surely, 2^15680121 is an apocalyptic number.

It is an amenable number.

15680121 is a deficient number, since it is larger than the sum of its proper divisors (5226711).

15680121 is an equidigital number, since it uses as much as digits as its factorization.

15680121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5226710.

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 15680121 is about 3959.8132531724. The cubic root of 15680121 is about 250.2936336488.

Adding to 15680121 its reverse (12108651), we get a palindrome (27788772).

The spelling of 15680121 in words is "fifteen million, six hundred eighty thousand, one hundred twenty-one".