121555257 has 4 divisors (see below), whose sum is σ = 162073680. Its totient is φ = 81036836.

The previous prime is 121555229. The next prime is 121555267. The reversal of 121555257 is 752555121.

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.

It is a cyclic number.

It is not a de Polignac number, because 121555257 - 2¹² = 121551161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121555267) 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, 20259207 + ... + 20259212.

It is an arithmetic number, because the mean of its divisors is an integer number (40518420).

Almost surely, 2^121555257 is an apocalyptic number.

It is an amenable number.

121555257 is a deficient number, since it is larger than the sum of its proper divisors (40518423).

121555257 is an equidigital number, since it uses as much as digits as its factorization.

121555257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40518422.

The product of its digits is 17500, while the sum is 33.

The square root of 121555257 is about 11025.2100660260. The cubic root of 121555257 is about 495.3641601496.

The spelling of 121555257 in words is "one hundred twenty-one million, five hundred fifty-five thousand, two hundred fifty-seven".