21000001220220 has 96 divisors (see below), whose sum is σ = 64179600145920. Its totient is φ = 5088199714560.

The previous prime is 21000001220203. The next prime is 21000001220249. The reversal of 21000001220220 is 2202210000012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21000001220196 and 21000001220205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7226647 + ... + 9706926.

It is an arithmetic number, because the mean of its divisors is an integer number (668537501520).

Almost surely, 2^{21000001220220} is an apocalyptic number.

21000001220220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000001220220 is an abundant number, since it is smaller than the sum of its proper divisors (43179598925700).

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

21000001220220 is a wasteful number, since it uses less digits than its factorization.

21000001220220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16935475 (or 16935473 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21000001220220 its reverse (2202210000012), we get a palindrome (23202211220232).

The spelling of 21000001220220 in words is "twenty-one trillion, one million, two hundred twenty thousand, two hundred twenty".