2100100001220 has 72 divisors (see below), whose sum is σ = 6860326678296. Its totient is φ = 516947692032.

The previous prime is 2100100001183. The next prime is 2100100001231. The reversal of 2100100001220 is 221000010012.

It can be written as a sum of positive squares in 4 ways, for example, as 55240041024 + 2044859960196 = 235032^2 + 1429986^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 448736977 + ... + 448741656.

Almost surely, 2^{2100100001220} is an apocalyptic number.

2100100001220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2100100001220 is an abundant number, since it is smaller than the sum of its proper divisors (4760226677076).

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

2100100001220 is a wasteful number, since it uses less digits than its factorization.

2100100001220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897478661 (or 897478656 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 2100100001220 its reverse (221000010012), we get a palindrome (2321100011232).

The spelling of 2100100001220 in words is "two trillion, one hundred billion, one hundred million, one thousand, two hundred twenty".