121221020 has 24 divisors (see below), whose sum is σ = 255150000.
Its totient is φ = 48376832.
The previous prime is 121221019. The next prime is 121221029. The reversal of 121221020 is 20122121.
It is a happy number.
It is a junction number, because it is equal to n+sod(n) for n = 121220992 and 121221010.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (121221029) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (17) of ones.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2231 + ... + 15729.
It is an arithmetic number, because the mean of its divisors is an integer number (10631250).
Almost surely, 2121221020 is an apocalyptic number.
121221020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is an amenable number.
121221020 is an abundant number, since it is smaller than the sum of its proper divisors (133928980).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
121221020 is a wasteful number, since it uses less digits than its factorization.
121221020 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 13957 (or 13955 counting only the distinct ones).
The product of its (nonzero) digits is 16, while the sum is 11.
The square root of 121221020 is about 11010.0417801205.
The cubic root of 121221020 is about 494.9097138328.
Adding to 121221020 its reverse (20122121), we get a palindrome (141343141).
The spelling of 121221020 in words is "one hundred twenty-one million, two hundred twenty-one thousand, twenty".