21120221202120 has 96 divisors (see below), whose sum is σ = 68679877102200. Its totient is φ = 5628846007296.

The previous prime is 21120221202089. The next prime is 21120221202161. The reversal of 21120221202120 is 2120212202112.

It is a happy number.

21120221202120 is a `hidden beast` number, since 2 + 1 + 120 + 221 + 202 + 120 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 17103700178244 + 4016521023876 = 4135662^2 + 2004126^2 .

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 = 21120221202093 and 21120221202102.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16102315 + ... + 17364474.

Almost surely, 2^{21120221202120} is an apocalyptic number.

21120221202120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120221202120 is an abundant number, since it is smaller than the sum of its proper divisors (47559655900080).

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

21120221202120 is a wasteful number, since it uses less digits than its factorization.

21120221202120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33468559 (or 33468552 counting only the distinct ones).

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

Adding to 21120221202120 its reverse (2120212202112), we get a palindrome (23240433404232).

The spelling of 21120221202120 in words is "twenty-one trillion, one hundred twenty billion, two hundred twenty-one million, two hundred two thousand, one hundred twenty".