21004433500 has 48 divisors (see below), whose sum is σ = 48288108960. Its totient is φ = 7959571200.

The previous prime is 21004433449. The next prime is 21004433533. The reversal of 21004433500 is 533440012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1095997 + ... + 1114996.

It is an arithmetic number, because the mean of its divisors is an integer number (1006002270).

Almost surely, 2^21004433500 is an apocalyptic number.

21004433500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21004433500 is an abundant number, since it is smaller than the sum of its proper divisors (27283675460).

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

21004433500 is a wasteful number, since it uses less digits than its factorization.

21004433500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2211031 (or 2211019 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 22.

Adding to 21004433500 its reverse (533440012), we get a palindrome (21537873512).

The spelling of 21004433500 in words is "twenty-one billion, four million, four hundred thirty-three thousand, five hundred".