21001100020220 has 12 divisors (see below), whose sum is σ = 44102310042504. Its totient is φ = 8400440008080.

The previous prime is 21001100020217. The next prime is 21001100020249. The reversal of 21001100020220 is 2202000110012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525027500486 + ... + 525027500525.

It is an arithmetic number, because the mean of its divisors is an integer number (3675192503542).

Almost surely, 2^{21001100020220} is an apocalyptic number.

21001100020220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001100020220 is an abundant number, since it is smaller than the sum of its proper divisors (23101210022284).

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

21001100020220 is a wasteful number, since it uses less digits than its factorization.

21001100020220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050055001020 (or 1050055001018 counting only the distinct ones).

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

Adding to 21001100020220 its reverse (2202000110012), we get a palindrome (23203100130232).

The spelling of 21001100020220 in words is "twenty-one trillion, one billion, one hundred million, twenty thousand, two hundred twenty".