121572157 has 4 divisors (see below), whose sum is σ = 138939616. Its totient is φ = 104204700.

The previous prime is 121572149. The next prime is 121572161. The reversal of 121572157 is 751275121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 751275121 = 37 ⋅20304733.

It is a cyclic number.

It is not a de Polignac number, because 121572157 - 2³ = 121572149 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 (121572107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8683719 + ... + 8683732.

It is an arithmetic number, because the mean of its divisors is an integer number (34734904).

Almost surely, 2^121572157 is an apocalyptic number.

It is an amenable number.

121572157 is a deficient number, since it is larger than the sum of its proper divisors (17367459).

121572157 is an equidigital number, since it uses as much as digits as its factorization.

121572157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17367458.

The product of its digits is 4900, while the sum is 31.

The square root of 121572157 is about 11025.9764646946. The cubic root of 121572157 is about 495.3871161467.

The spelling of 121572157 in words is "one hundred twenty-one million, five hundred seventy-two thousand, one hundred fifty-seven".