121537220 has 24 divisors (see below), whose sum is σ = 291689664. Its totient is φ = 41669856.

The previous prime is 121537187. The next prime is 121537223. The reversal of 121537220 is 22735121.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (121537223) by changing a digit.

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, 433922 + ... + 434201.

It is an arithmetic number, because the mean of its divisors is an integer number (12153736).

Almost surely, 2^121537220 is an apocalyptic number.

121537220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121537220 is an abundant number, since it is smaller than the sum of its proper divisors (170152444).

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

121537220 is a wasteful number, since it uses less digits than its factorization.

121537220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 868139 (or 868137 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 121537220 is about 11024.3920467298. The cubic root of 121537220 is about 495.3396573692.

The spelling of 121537220 in words is "one hundred twenty-one million, five hundred thirty-seven thousand, two hundred twenty".