21000121212200 has 96 divisors (see below), whose sum is σ = 53101678071960. Its totient is φ = 7677119616000.

The previous prime is 21000121212199. The next prime is 21000121212221. The reversal of 21000121212200 is 221212100012.

It can be written as a sum of positive squares in 12 ways, for example, as 7427837864836 + 13572283347364 = 2725406^2 + 3684058^2 .

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, 39722399 + ... + 40247598.

Almost surely, 2^{21000121212200} is an apocalyptic number.

21000121212200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000121212200 is an abundant number, since it is smaller than the sum of its proper divisors (32101556859760).

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

21000121212200 is a wasteful number, since it uses less digits than its factorization.

21000121212200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79970127 (or 79970118 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21000121212200 its reverse (221212100012), we get a palindrome (21221333312212).

The spelling of 21000121212200 in words is "twenty-one trillion, one hundred twenty-one million, two hundred twelve thousand, two hundred".