1200121220 has 24 divisors (see below), whose sum is σ = 2523696000. Its totient is φ = 479392992.

The previous prime is 1200121217. The next prime is 1200121229. The reversal of 1200121220 is 221210021.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1200121229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25820 + ... + 55379.

It is an arithmetic number, because the mean of its divisors is an integer number (105154000).

Almost surely, 2^1200121220 is an apocalyptic number.

1200121220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1200121220 is an abundant number, since it is smaller than the sum of its proper divisors (1323574780).

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

1200121220 is a wasteful number, since it uses less digits than its factorization.

1200121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81947 (or 81945 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1200121220 is about 34642.7657671844. The cubic root of 1200121220 is about 1062.6943500533.

Adding to 1200121220 its reverse (221210021), we get a palindrome (1421331241).

The spelling of 1200121220 in words is "one billion, two hundred million, one hundred twenty-one thousand, two hundred twenty".