121252139 has 4 divisors (see below), whose sum is σ = 123307320. Its totient is φ = 119196960.

The previous prime is 121252099. The next prime is 121252147. The reversal of 121252139 is 931252121.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121252139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121252169) 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, 1027502 + ... + 1027619.

It is an arithmetic number, because the mean of its divisors is an integer number (30826830).

Almost surely, 2^121252139 is an apocalyptic number.

121252139 is a deficient number, since it is larger than the sum of its proper divisors (2055181).

121252139 is an equidigital number, since it uses as much as digits as its factorization.

121252139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2055180.

The product of its digits is 1080, while the sum is 26.

The square root of 121252139 is about 11011.4548993310. The cubic root of 121252139 is about 494.9520601126.

The spelling of 121252139 in words is "one hundred twenty-one million, two hundred fifty-two thousand, one hundred thirty-nine".