2101221220 has 48 divisors (see below), whose sum is σ = 5054313600. Its totient is φ = 718792704.

The previous prime is 2101221193. The next prime is 2101221247. The reversal of 2101221220 is 221221012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2101221193) and next prime (2101221247).

It is a self number, because there is not a number n which added to its sum of digits gives 2101221220.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46147 + ... + 79573.

It is an arithmetic number, because the mean of its divisors is an integer number (105298200).

Almost surely, 2^2101221220 is an apocalyptic number.

2101221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2101221220 is an abundant number, since it is smaller than the sum of its proper divisors (2953092380).

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

2101221220 is a wasteful number, since it uses less digits than its factorization.

2101221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33892 (or 33890 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 2101221220 is about 45839.0796155420. The cubic root of 2101221220 is about 1280.8273500412.

Adding to 2101221220 its reverse (221221012), we get a palindrome (2322442232).

The spelling of 2101221220 in words is "two billion, one hundred one million, two hundred twenty-one thousand, two hundred twenty".