21004433100 has 324 divisors, whose sum is σ = 77568472800. Its totient is φ = 4739454720.

The previous prime is 21004433081. The next prime is 21004433123. The reversal of 21004433100 is 133440012.

21004433100 is a `hidden beast` number, since 210 + 0 + 443 + 3 + 10 + 0 = 666.

It is a super-2 number, since 2×21004433100² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 3480886 + ... + 3486914.

Almost surely, 2^21004433100 is an apocalyptic number.

21004433100 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 21004433100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38784236400).

21004433100 is an abundant number, since it is smaller than the sum of its proper divisors (56564039700).

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

21004433100 is a wasteful number, since it uses less digits than its factorization.

21004433100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6142 (or 6125 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21004433100 its reverse (133440012), we get a palindrome (21137873112).

The spelling of 21004433100 in words is "twenty-one billion, four million, four hundred thirty-three thousand, one hundred".