121220251 has 16 divisors (see below), whose sum is σ = 132641280. Its totient is φ = 110315520.

The previous prime is 121220243. The next prime is 121220269. The reversal of 121220251 is 152022121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 121220251 - 2³ = 121220243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121220201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119635 + ... + 120643.

It is an arithmetic number, because the mean of its divisors is an integer number (8290080).

Almost surely, 2^121220251 is an apocalyptic number.

121220251 is a deficient number, since it is larger than the sum of its proper divisors (11421029).

121220251 is a wasteful number, since it uses less digits than its factorization.

121220251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1254.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 121220251 is about 11010.0068574002. The cubic root of 121220251 is about 494.9086672971.

Subtracting from 121220251 its sum of digits (16), we obtain a triangular number (121220235 = T₁₅₅₇₀).

Adding to 121220251 its reverse (152022121), we get a palindrome (273242372).

The spelling of 121220251 in words is "one hundred twenty-one million, two hundred twenty thousand, two hundred fifty-one".