21503244000 has 384 divisors, whose sum is σ = 80883339264. Its totient is φ = 4892160000.

The previous prime is 21503243981. The next prime is 21503244011. The reversal of 21503244000 is 44230512.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23603545 + ... + 23604455.

It is an arithmetic number, because the mean of its divisors is an integer number (210633696).

Almost surely, 2^21503244000 is an apocalyptic number.

21503244000 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 21503244000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40441669632).

21503244000 is an abundant number, since it is smaller than the sum of its proper divisors (59380095264).

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

21503244000 is a wasteful number, since it uses less digits than its factorization.

21503244000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1227 (or 1209 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

Adding to 21503244000 its reverse (44230512), we get a palindrome (21547474512).

The spelling of 21503244000 in words is "twenty-one billion, five hundred three million, two hundred forty-four thousand".