21021021222120 has 160 divisors (see below), whose sum is σ = 73725900779520. Its totient is φ = 5361883655040.

The previous prime is 21021021222083. The next prime is 21021021222121. The reversal of 21021021222120 is 2122212012012.

It is a happy number.

21021021222120 is a `hidden beast` number, since 2 + 1 + 0 + 210 + 212 + 221 + 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 = 21021021222093 and 21021021222102.

It is not an unprimeable number, because it can be changed into a prime (21021021222121) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 140968296 + ... + 141117335.

It is an arithmetic number, because the mean of its divisors is an integer number (460786879872).

Almost surely, 2^{21021021222120} is an apocalyptic number.

21021021222120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021021222120 is an abundant number, since it is smaller than the sum of its proper divisors (52704879557400).

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

21021021222120 is a wasteful number, since it uses less digits than its factorization.

21021021222120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282085677 (or 282085664 counting only the distinct ones).

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

Adding to 21021021222120 its reverse (2122212012012), we get a palindrome (23143233234132).

The spelling of 21021021222120 in words is "twenty-one trillion, twenty-one billion, twenty-one million, two hundred twenty-two thousand, one hundred twenty".