21012111221200 has 60 divisors (see below), whose sum is σ = 55070833330368. Its totient is φ = 7640767715200.

The previous prime is 21012111221177. The next prime is 21012111221207. The reversal of 21012111221200 is 212211121012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012111221207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2387735512 + ... + 2387744311.

Almost surely, 2^{21012111221200} is an apocalyptic number.

21012111221200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012111221200 is an abundant number, since it is smaller than the sum of its proper divisors (34058722109168).

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

21012111221200 is a wasteful number, since it uses less digits than its factorization.

21012111221200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4775479852 (or 4775479841 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21012111221200 its reverse (212211121012), we get a palindrome (21224322342212).

The spelling of 21012111221200 in words is "twenty-one trillion, twelve billion, one hundred eleven million, two hundred twenty-one thousand, two hundred".