21420212200 has 96 divisors (see below), whose sum is σ = 51470377560. Its totient is φ = 8284774400.

The previous prime is 21420212183. The next prime is 21420212221. The reversal of 21420212200 is 221202412.

It can be written as a sum of positive squares in 12 ways, for example, as 9656206756 + 11764005444 = 98266^2 + 108462^2 .

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, 915042 + ... + 938158.

Almost surely, 2^21420212200 is an apocalyptic number.

21420212200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21420212200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25735188780).

21420212200 is an abundant number, since it is smaller than the sum of its proper divisors (30050165360).

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

21420212200 is a wasteful number, since it uses less digits than its factorization.

21420212200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23287 (or 23278 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21420212200 its reverse (221202412), we get a palindrome (21641414612).

The spelling of 21420212200 in words is "twenty-one billion, four hundred twenty million, two hundred twelve thousand, two hundred".