121231139 has 2 divisors, whose sum is σ = 121231140. Its totient is φ = 121231138.

The previous prime is 121231133. The next prime is 121231157. The reversal of 121231139 is 931132121.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121231139 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121231133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60615569 + 60615570.

It is an arithmetic number, because the mean of its divisors is an integer number (60615570).

Almost surely, 2^121231139 is an apocalyptic number.

121231139 is a deficient number, since it is larger than the sum of its proper divisors (1).

121231139 is an equidigital number, since it uses as much as digits as its factorization.

121231139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 324, while the sum is 23.

The square root of 121231139 is about 11010.5013055719. The cubic root of 121231139 is about 494.9234844149.

The spelling of 121231139 in words is "one hundred twenty-one million, two hundred thirty-one thousand, one hundred thirty-nine".