202123139 has 2 divisors, whose sum is σ = 202123140. Its totient is φ = 202123138.

The previous prime is 202123111. The next prime is 202123147. The reversal of 202123139 is 931321202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 202123139 - 2²⁰ = 201074563 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (202123189) 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 as a sum of consecutive naturals, namely, 101061569 + 101061570.

It is an arithmetic number, because the mean of its divisors is an integer number (101061570).

Almost surely, 2^202123139 is an apocalyptic number.

202123139 is a deficient number, since it is larger than the sum of its proper divisors (1).

202123139 is an equidigital number, since it uses as much as digits as its factorization.

202123139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 202123139 is about 14217.0017584581. The cubic root of 202123139 is about 586.8656333067.

The spelling of 202123139 in words is "two hundred two million, one hundred twenty-three thousand, one hundred thirty-nine".