21021000121220 has 48 divisors (see below), whose sum is σ = 48165850454400. Its totient is φ = 7642627000320.

The previous prime is 21021000121211. The next prime is 21021000121229. The reversal of 21021000121220 is 2212100012012.

It is an interprime number because it is at equal distance from previous prime (21021000121211) and next prime (21021000121229).

It is a junction number, because it is equal to n+sod(n) for n = 21021000121195 and 21021000121204.

It is not an unprimeable number, because it can be changed into a prime (21021000121229) 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, 7353560 + ... + 9803919.

It is an arithmetic number, because the mean of its divisors is an integer number (1003455217800).

Almost surely, 2^{21021000121220} is an apocalyptic number.

21021000121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021000121220 is an abundant number, since it is smaller than the sum of its proper divisors (27144850333180).

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

21021000121220 is a wasteful number, since it uses less digits than its factorization.

21021000121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17163068 (or 17163066 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21021000121220 its reverse (2212100012012), we get a palindrome (23233100133232).

The spelling of 21021000121220 in words is "twenty-one trillion, twenty-one billion, one hundred twenty-one thousand, two hundred twenty".