12691139 has 4 divisors (see below), whose sum is σ = 12744480. Its totient is φ = 12637800.

The previous prime is 12691109. The next prime is 12691169. The reversal of 12691139 is 93119621.

12691139 = T₁₉₉ + T₂₀₀ + ... + T₄₃₇.

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

It is an interprime number because it is at equal distance from previous prime (12691109) and next prime (12691169).

It is a cyclic number.

It is not a de Polignac number, because 12691139 - 2⁸ = 12690883 is a prime.

It is a super-2 number, since 2×12691139² = 322130018234642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12691109) 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, 26312 + ... + 26789.

It is an arithmetic number, because the mean of its divisors is an integer number (3186120).

Almost surely, 2^12691139 is an apocalyptic number.

12691139 is a deficient number, since it is larger than the sum of its proper divisors (53341).

12691139 is an equidigital number, since it uses as much as digits as its factorization.

12691139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53340.

The product of its digits is 2916, while the sum is 32.

The square root of 12691139 is about 3562.4624910306. The cubic root of 12691139 is about 233.2563812003.

The spelling of 12691139 in words is "twelve million, six hundred ninety-one thousand, one hundred thirty-nine".