12399961 has 4 divisors (see below), whose sum is σ = 14171392. Its totient is φ = 10628532.

The previous prime is 12399941. The next prime is 12399973. The reversal of 12399961 is 16999321.

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: 16999321 = 2347 ⋅7243.

It is a cyclic number.

It is not a de Polignac number, because 12399961 - 2⁷ = 12399833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12399901) 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, 885705 + ... + 885718.

It is an arithmetic number, because the mean of its divisors is an integer number (3542848).

Almost surely, 2^12399961 is an apocalyptic number.

It is an amenable number.

12399961 is a deficient number, since it is larger than the sum of its proper divisors (1771431).

12399961 is an equidigital number, since it uses as much as digits as its factorization.

12399961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1771430.

The product of its digits is 26244, while the sum is 40.

The square root of 12399961 is about 3521.3578346996. The cubic root of 12399961 is about 231.4586627938.

The spelling of 12399961 in words is "twelve million, three hundred ninety-nine thousand, nine hundred sixty-one".