121128157 has 4 divisors (see below), whose sum is σ = 125305020. Its totient is φ = 116951296.

The previous prime is 121128149. The next prime is 121128181. The reversal of 121128157 is 751821121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 27154521 + 93973636 = 5211^2 + 9694^2 .

It is a cyclic number.

It is not a de Polignac number, because 121128157 - 2³ = 121128149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121128197) 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, 2088388 + ... + 2088445.

It is an arithmetic number, because the mean of its divisors is an integer number (31326255).

Almost surely, 2^121128157 is an apocalyptic number.

It is an amenable number.

121128157 is a deficient number, since it is larger than the sum of its proper divisors (4176863).

121128157 is an equidigital number, since it uses as much as digits as its factorization.

121128157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4176862.

The product of its digits is 1120, while the sum is 28.

The square root of 121128157 is about 11005.8237765285. The cubic root of 121128157 is about 494.7833041239.

Adding to 121128157 its reverse (751821121), we get a palindrome (872949278).

The spelling of 121128157 in words is "one hundred twenty-one million, one hundred twenty-eight thousand, one hundred fifty-seven".