21201021022120 has 32 divisors (see below), whose sum is σ = 47760400050120. Its totient is φ = 8470079031040.

The previous prime is 21201021022081. The next prime is 21201021022127. The reversal of 21201021022120 is 2122012010212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 16035555731364 + 5165465290756 = 4004442^2 + 2272766^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21201021022094 and 21201021022103.

It is not an unprimeable number, because it can be changed into a prime (21201021022127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 322759807 + ... + 322825486.

Almost surely, 2^{21201021022120} is an apocalyptic number.

21201021022120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201021022120 is an abundant number, since it is smaller than the sum of its proper divisors (26559379028000).

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

21201021022120 is a wasteful number, since it uses less digits than its factorization.

21201021022120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645586125 (or 645586121 counting only the distinct ones).

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

Adding to 21201021022120 its reverse (2122012010212), we get a palindrome (23323033032332).

The spelling of 21201021022120 in words is "twenty-one trillion, two hundred one billion, twenty-one million, twenty-two thousand, one hundred twenty".