21213631200 has 144 divisors (see below), whose sum is σ = 69129075456. Its totient is φ = 5650521600.

The previous prime is 21213631181. The next prime is 21213631217. The reversal of 21213631200 is 213631212.

It is a Cunningham number, because it is equal to 145649²-1.

It is a super-2 number, since 2×21213631200² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 2325849 + ... + 2334951.

It is an arithmetic number, because the mean of its divisors is an integer number (480063024).

Almost surely, 2^21213631200 is an apocalyptic number.

21213631200 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 21213631200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34564537728).

21213631200 is an abundant number, since it is smaller than the sum of its proper divisors (47915444256).

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

21213631200 is a wasteful number, since it uses less digits than its factorization.

21213631200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10097 (or 10084 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The spelling of 21213631200 in words is "twenty-one billion, two hundred thirteen million, six hundred thirty-one thousand, two hundred".