21201212222000 has 80 divisors (see below), whose sum is σ = 51271031708832. Its totient is φ = 8479409529600.

The previous prime is 21201212221999. The next prime is 21201212222009. The reversal of 21201212222000 is 22221210212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 21201212222000.

It is not an unprimeable number, because it can be changed into a prime (21201212222009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15197867 + ... + 16534133.

Almost surely, 2^{21201212222000} is an apocalyptic number.

21201212222000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201212222000 is an abundant number, since it is smaller than the sum of its proper divisors (30069819486832).

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

21201212222000 is a wasteful number, since it uses less digits than its factorization.

21201212222000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344223 (or 1344207 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21201212222000 its reverse (22221210212), we get a palindrome (21223433432212).

The spelling of 21201212222000 in words is "twenty-one trillion, two hundred one billion, two hundred twelve million, two hundred twenty-two thousand".