21189949200 has 360 divisors, whose sum is σ = 88985340288. Its totient is φ = 4558417920.

The previous prime is 21189949199. The next prime is 21189949211. The reversal of 21189949200 is 294998112.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 403669 + ... + 453131.

Almost surely, 2^21189949200 is an apocalyptic number.

21189949200 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 21189949200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44492670144).

21189949200 is an abundant number, since it is smaller than the sum of its proper divisors (67795391088).

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

21189949200 is a wasteful number, since it uses less digits than its factorization.

21189949200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49511 (or 49497 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The spelling of 21189949200 in words is "twenty-one billion, one hundred eighty-nine million, nine hundred forty-nine thousand, two hundred".