121220257 has 4 divisors (see below), whose sum is σ = 121242880. Its totient is φ = 121197636.

The previous prime is 121220243. The next prime is 121220269. The reversal of 121220257 is 752022121.

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 a de Polignac number, because none of the positive numbers 2^k-121220257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121220287) 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, 1768 + ... + 15670.

It is an arithmetic number, because the mean of its divisors is an integer number (30310720).

Almost surely, 2^121220257 is an apocalyptic number.

It is an amenable number.

121220257 is a deficient number, since it is larger than the sum of its proper divisors (22623).

121220257 is an equidigital number, since it uses as much as digits as its factorization.

121220257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22622.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 121220257 is about 11010.0071298796. The cubic root of 121220257 is about 494.9086754625.

Subtracting from 121220257 its sum of digits (22), we obtain a triangular number (121220235 = T₁₅₅₇₀).

Adding to 121220257 its reverse (752022121), we get a palindrome (873242378).

The spelling of 121220257 in words is "one hundred twenty-one million, two hundred twenty thousand, two hundred fifty-seven".