21217699200 has 192 divisors, whose sum is σ = 72296600400. Its totient is φ = 5462876160.

The previous prime is 21217699193. The next prime is 21217699207. The reversal of 21217699200 is 299671212.

It is an interprime number because it is at equal distance from previous prime (21217699193) and next prime (21217699207).

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21217699207) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 240294 + ... + 316506.

Almost surely, 2^21217699200 is an apocalyptic number.

21217699200 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 21217699200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36148300200).

21217699200 is an abundant number, since it is smaller than the sum of its proper divisors (51078901200).

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

21217699200 is a wasteful number, since it uses less digits than its factorization.

21217699200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76269 (or 76252 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 39.

The spelling of 21217699200 in words is "twenty-one billion, two hundred seventeen million, six hundred ninety-nine thousand, two hundred".