121636220 has 12 divisors (see below), whose sum is σ = 255436104. Its totient is φ = 48654480.

The previous prime is 121636201. The next prime is 121636231. The reversal of 121636220 is 22636121.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3040886 + ... + 3040925.

It is an arithmetic number, because the mean of its divisors is an integer number (21286342).

Almost surely, 2^121636220 is an apocalyptic number.

121636220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121636220 is an abundant number, since it is smaller than the sum of its proper divisors (133799884).

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

121636220 is a wasteful number, since it uses less digits than its factorization.

121636220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6081820 (or 6081818 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 121636220 is about 11028.8811762572. The cubic root of 121636220 is about 495.4741163633.

Subtracting from 121636220 its reverse (22636121), we obtain a palindrome (99000099).

The spelling of 121636220 in words is "one hundred twenty-one million, six hundred thirty-six thousand, two hundred twenty".