21201122001220 has 48 divisors (see below), whose sum is σ = 53560729272960. Its totient is φ = 6886379476224.

The previous prime is 21201122001211. The next prime is 21201122001229. The reversal of 21201122001220 is 2210022110212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21201122001211) and next prime (21201122001229).

It is a super-2 number, since 2×21201122001220² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21201122001194 and 21201122001203.

It is not an unprimeable number, because it can be changed into a prime (21201122001229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3985170649 + ... + 3985175968.

It is an arithmetic number, because the mean of its divisors is an integer number (1115848526520).

Almost surely, 2^{21201122001220} is an apocalyptic number.

21201122001220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201122001220 is an abundant number, since it is smaller than the sum of its proper divisors (32359607271740).

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

21201122001220 is a wasteful number, since it uses less digits than its factorization.

21201122001220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7970346652 (or 7970346650 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21201122001220 its reverse (2210022110212), we get a palindrome (23411144111432).

The spelling of 21201122001220 in words is "twenty-one trillion, two hundred one billion, one hundred twenty-two million, one thousand, two hundred twenty".