21201022121200 has 60 divisors (see below), whose sum is σ = 50937403993920. Its totient is φ = 8480084462080.

The previous prime is 21201022121177. The next prime is 21201022121267. The reversal of 21201022121200 is 212122010212.

It is a happy number.

It is a super-2 number, since 2×21201022121200² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9595137 + ... + 11596063.

It is an arithmetic number, because the mean of its divisors is an integer number (848956733232).

Almost surely, 2^{21201022121200} is an apocalyptic number.

21201022121200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201022121200 is an abundant number, since it is smaller than the sum of its proper divisors (29736381872720).

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

21201022121200 is a wasteful number, since it uses less digits than its factorization.

21201022121200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2027434 (or 2027423 counting only the distinct ones).

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

Adding to 21201022121200 its reverse (212122010212), we get a palindrome (21413144131412).

The spelling of 21201022121200 in words is "twenty-one trillion, two hundred one billion, twenty-two million, one hundred twenty-one thousand, two hundred".