121251220 has 24 divisors (see below), whose sum is σ = 261510984. Its totient is φ = 47189376.

The previous prime is 121251209. The next prime is 121251281. The reversal of 121251220 is 22152121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 68194564 + 53056656 = 8258^2 + 7284^2 .

It is a junction number, because it is equal to n+sod(n) for n = 121251194 and 121251203.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81187 + ... + 82666.

It is an arithmetic number, because the mean of its divisors is an integer number (10896291).

Almost surely, 2^121251220 is an apocalyptic number.

121251220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121251220 is an abundant number, since it is smaller than the sum of its proper divisors (140259764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121251220 is a wasteful number, since it uses less digits than its factorization.

121251220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163899 (or 163897 counting only the distinct ones).

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

The square root of 121251220 is about 11011.4131699796. The cubic root of 121251220 is about 494.9508096546.

Subtracting from 121251220 its reverse (22152121), we obtain a palindrome (99099099).

The spelling of 121251220 in words is "one hundred twenty-one million, two hundred fifty-one thousand, two hundred twenty".