21000100022220 has 96 divisors (see below), whose sum is σ = 64234976762880. Its totient is φ = 5083852648960.

The previous prime is 21000100022207. The next prime is 21000100022249. The reversal of 21000100022220 is 2222000100012.

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 = 21000100022196 and 21000100022205.

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, 21652257 + ... + 22601336.

It is an arithmetic number, because the mean of its divisors is an integer number (669114341280).

Almost surely, 2^{21000100022220} is an apocalyptic number.

21000100022220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000100022220 is an abundant number, since it is smaller than the sum of its proper divisors (43234876740660).

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

21000100022220 is a wasteful number, since it uses less digits than its factorization.

21000100022220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44254335 (or 44254333 counting only the distinct ones).

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

Adding to 21000100022220 its reverse (2222000100012), we get a palindrome (23222100122232).

The spelling of 21000100022220 in words is "twenty-one trillion, one hundred million, twenty-two thousand, two hundred twenty".