21143533500 has 72 divisors (see below), whose sum is σ = 66700814544. Its totient is φ = 5638274400.

The previous prime is 21143533459. The next prime is 21143533501. The reversal of 21143533500 is 533534112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143533501) 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, 2344782 + ... + 2353781.

It is an arithmetic number, because the mean of its divisors is an integer number (926400202).

Almost surely, 2^21143533500 is an apocalyptic number.

21143533500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21143533500 is an abundant number, since it is smaller than the sum of its proper divisors (45557281044).

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

21143533500 is a wasteful number, since it uses less digits than its factorization.

21143533500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4698588 (or 4698573 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 27.

The spelling of 21143533500 in words is "twenty-one billion, one hundred forty-three million, five hundred thirty-three thousand, five hundred".