12139381 has 2 divisors, whose sum is σ = 12139382. Its totient is φ = 12139380.

The previous prime is 12139349. The next prime is 12139409. The reversal of 12139381 is 18393121.

It is an a-pointer prime, because the next prime (12139409) can be obtained adding 12139381 to its sum of digits (28).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9400356 + 2739025 = 3066^2 + 1655^2 .

It is a cyclic number.

It is not a de Polignac number, because 12139381 - 2⁵ = 12139349 is a prime.

It is a super-2 number, since 2×12139381² = 294729142126322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12139181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6069690 + 6069691.

It is an arithmetic number, because the mean of its divisors is an integer number (6069691).

Almost surely, 2^12139381 is an apocalyptic number.

It is an amenable number.

12139381 is a deficient number, since it is larger than the sum of its proper divisors (1).

12139381 is an equidigital number, since it uses as much as digits as its factorization.

12139381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 28.

The square root of 12139381 is about 3484.1614486129. The cubic root of 12139381 is about 229.8258353831.

The spelling of 12139381 in words is "twelve million, one hundred thirty-nine thousand, three hundred eighty-one".