21123201200 has 60 divisors (see below), whose sum is σ = 51359999208. Its totient is φ = 8347468800.

The previous prime is 21123201157. The next prime is 21123201223. The reversal of 21123201200 is 210232112.

It is a happy 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, 284921 + ... + 351320.

Almost surely, 2^21123201200 is an apocalyptic number.

21123201200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21123201200 is an abundant number, since it is smaller than the sum of its proper divisors (30236798008).

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

21123201200 is a wasteful number, since it uses less digits than its factorization.

21123201200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636342 (or 636331 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21123201200 its reverse (210232112), we get a palindrome (21333433312).

The spelling of 21123201200 in words is "twenty-one billion, one hundred twenty-three million, two hundred one thousand, two hundred".