121705139 has 4 divisors (see below), whose sum is σ = 121881960. Its totient is φ = 121528320.

The previous prime is 121705069. The next prime is 121705153. The reversal of 121705139 is 931507121.

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

It is a cyclic number.

It is not a de Polignac number, because 121705139 - 2⁸ = 121704883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121705169) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87374 + ... + 88755.

It is an arithmetic number, because the mean of its divisors is an integer number (30470490).

Almost surely, 2^121705139 is an apocalyptic number.

121705139 is a deficient number, since it is larger than the sum of its proper divisors (176821).

121705139 is an equidigital number, since it uses as much as digits as its factorization.

121705139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176820.

The product of its (nonzero) digits is 1890, while the sum is 29.

The square root of 121705139 is about 11032.0052121090. The cubic root of 121705139 is about 495.5676771281.

The spelling of 121705139 in words is "one hundred twenty-one million, seven hundred five thousand, one hundred thirty-nine".