21200120022120 has 128 divisors (see below), whose sum is σ = 68985449366400. Its totient is φ = 5180947928064.

The previous prime is 21200120022091. The next prime is 21200120022121. The reversal of 21200120022120 is 2122002100212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21200120022120.

It is not an unprimeable number, because it can be changed into a prime (21200120022121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48667407 + ... + 49101086.

It is an arithmetic number, because the mean of its divisors is an integer number (538948823175).

Almost surely, 2^{21200120022120} is an apocalyptic number.

21200120022120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21200120022120 is an abundant number, since it is smaller than the sum of its proper divisors (47785329344280).

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

21200120022120 is a wasteful number, since it uses less digits than its factorization.

21200120022120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97768659 (or 97768655 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21200120022120 its reverse (2122002100212), we get a palindrome (23322122122332).

The spelling of 21200120022120 in words is "twenty-one trillion, two hundred billion, one hundred twenty million, twenty-two thousand, one hundred twenty".