21221222101020 has 72 divisors (see below), whose sum is σ = 64371475633920. Its totient is φ = 5658954295680.

The previous prime is 21221222101019. The next prime is 21221222101039. The reversal of 21221222101020 is 2010122212212.

It is a happy number.

21221222101020 is a `hidden beast` number, since 212 + 212 + 2 + 210 + 10 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21221222100984 and 21221222101002.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35008110 + ... + 35609130.

Almost surely, 2^{21221222101020} is an apocalyptic number.

21221222101020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221222101020 is an abundant number, since it is smaller than the sum of its proper divisors (43150253532900).

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

21221222101020 is a wasteful number, since it uses less digits than its factorization.

21221222101020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797195 (or 797190 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21221222101020 its reverse (2010122212212), we get a palindrome (23231344313232).

The spelling of 21221222101020 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-two million, one hundred one thousand, twenty".