21503250024 has 32 divisors (see below), whose sum is σ = 54233867520. Its totient is φ = 7104317696.

The previous prime is 21503250011. The next prime is 21503250031. The reversal of 21503250024 is 42005230512.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 21503249976 and 21503250003.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3961752 + ... + 3967175.

It is an arithmetic number, because the mean of its divisors is an integer number (1694808360).

Almost surely, 2^21503250024 is an apocalyptic number.

21503250024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21503250024 is an abundant number, since it is smaller than the sum of its proper divisors (32730617496).

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

21503250024 is a wasteful number, since it uses less digits than its factorization.

21503250024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7929049 (or 7929045 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

Adding to 21503250024 its reverse (42005230512), we get a palindrome (63508480536).

The spelling of 21503250024 in words is "twenty-one billion, five hundred three million, two hundred fifty thousand, twenty-four".