1200021221 has 24 divisors (see below), whose sum is σ = 1426249440. Its totient is φ = 1006502112.

The previous prime is 1200021217. The next prime is 1200021227. The reversal of 1200021221 is 1221200021.

It is a happy number.

It is not a de Polignac number, because 1200021221 - 2² = 1200021217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200021227) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 441950 + ... + 444656.

It is an arithmetic number, because the mean of its divisors is an integer number (59427060).

Almost surely, 2^1200021221 is an apocalyptic number.

It is an amenable number.

1200021221 is a deficient number, since it is larger than the sum of its proper divisors (226228219).

1200021221 is a wasteful number, since it uses less digits than its factorization.

1200021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2913 (or 2906 counting only the distinct ones).

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

The square root of 1200021221 is about 34641.3224487750. The cubic root of 1200021221 is about 1062.6648332228.

Adding to 1200021221 its reverse (1221200021), we get a palindrome (2421221242).

The spelling of 1200021221 in words is "one billion, two hundred million, twenty-one thousand, two hundred twenty-one".