21220111010100 has 72 divisors (see below), whose sum is σ = 64628267935840. Its totient is φ = 5360870148480.

The previous prime is 21220111010069. The next prime is 21220111010101. The reversal of 21220111010100 is 101011102212.

It is a super-2 number, since 2×21220111010100² (a number of 27 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220111010101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1861407547 + ... + 1861418946.

Almost surely, 2^{21220111010100} is an apocalyptic number.

21220111010100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220111010100 is an abundant number, since it is smaller than the sum of its proper divisors (43408156925740).

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

21220111010100 is a wasteful number, since it uses less digits than its factorization.

21220111010100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3722826529 (or 3722826522 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21220111010100 its reverse (101011102212), we get a palindrome (21321122112312).

The spelling of 21220111010100 in words is "twenty-one trillion, two hundred twenty billion, one hundred eleven million, ten thousand, one hundred".