21221300023220 has 72 divisors (see below), whose sum is σ = 49025646708192. Its totient is φ = 7710334202560.

The previous prime is 21221300023201. The next prime is 21221300023229. The reversal of 21221300023220 is 2232000312212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21221300023192 and 21221300023201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221300023229) by changing a digit.

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, 821282 + ... + 6566361.

It is an arithmetic number, because the mean of its divisors is an integer number (680911759836).

Almost surely, 2^{21221300023220} is an apocalyptic number.

21221300023220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221300023220 is an abundant number, since it is smaller than the sum of its proper divisors (27804346684972).

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

21221300023220 is a wasteful number, since it uses less digits than its factorization.

21221300023220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7388861 (or 7388848 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21221300023220 its reverse (2232000312212), we get a palindrome (23453300335432).

The spelling of 21221300023220 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred million, twenty-three thousand, two hundred twenty".