121642139 has 2 divisors, whose sum is σ = 121642140. Its totient is φ = 121642138.

The previous prime is 121642111. The next prime is 121642151. The reversal of 121642139 is 931246121.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121642139 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121642159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60821069 + 60821070.

It is an arithmetic number, because the mean of its divisors is an integer number (60821070).

Almost surely, 2^121642139 is an apocalyptic number.

121642139 is a deficient number, since it is larger than the sum of its proper divisors (1).

121642139 is an equidigital number, since it uses as much as digits as its factorization.

121642139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 29.

The square root of 121642139 is about 11029.1495139018. The cubic root of 121642139 is about 495.4821530696.

The spelling of 121642139 in words is "one hundred twenty-one million, six hundred forty-two thousand, one hundred thirty-nine".