12139971 has 4 divisors (see below), whose sum is σ = 16186632. Its totient is φ = 8093312.

The previous prime is 12139961. The next prime is 12139979. The reversal of 12139971 is 17993121.

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

It is a cyclic number.

It is not a de Polignac number, because 12139971 - 2¹⁰ = 12138947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12139979) 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, 2023326 + ... + 2023331.

It is an arithmetic number, because the mean of its divisors is an integer number (4046658).

Almost surely, 2^12139971 is an apocalyptic number.

12139971 is a deficient number, since it is larger than the sum of its proper divisors (4046661).

12139971 is an equidigital number, since it uses as much as digits as its factorization.

12139971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4046660.

The product of its digits is 3402, while the sum is 33.

The square root of 12139971 is about 3484.2461164504. The cubic root of 12139971 is about 229.8295586659.

The spelling of 12139971 in words is "twelve million, one hundred thirty-nine thousand, nine hundred seventy-one".