2100001220 has 48 divisors (see below), whose sum is σ = 4705760640. Its totient is φ = 784878336.

The previous prime is 2100001207. The next prime is 2100001231. The reversal of 2100001220 is 221000012.

It is a junction number, because it is equal to n+sod(n) for n = 2100001198 and 2100001207.

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, 10112 + ... + 65591.

It is an arithmetic number, because the mean of its divisors is an integer number (98036680).

Almost surely, 2^2100001220 is an apocalyptic number.

2100001220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2100001220 is an abundant number, since it is smaller than the sum of its proper divisors (2605759420).

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

2100001220 is a wasteful number, since it uses less digits than its factorization.

2100001220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75804 (or 75802 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 2100001220 is about 45825.7702608478. The cubic root of 2100001220 is about 1280.5794129726.

Adding to 2100001220 its reverse (221000012), we get a palindrome (2321001232).

The spelling of 2100001220 in words is "two billion, one hundred million, one thousand, two hundred twenty".