21000000504 has 32 divisors (see below), whose sum is σ = 60000001920. Its totient is φ = 6000000096.

The previous prime is 21000000493. The next prime is 21000000557. The reversal of 21000000504 is 40500000012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 21000000504.

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 7 ways as a sum of consecutive naturals, for example, 62499834 + ... + 62500169.

It is an arithmetic number, because the mean of its divisors is an integer number (1875000060).

Almost surely, 2^21000000504 is an apocalyptic number.

21000000504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21000000504 is an abundant number, since it is smaller than the sum of its proper divisors (39000001416).

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

21000000504 is a wasteful number, since it uses less digits than its factorization.

21000000504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125000019 (or 125000015 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 12.

Adding to 21000000504 its reverse (40500000012), we get a palindrome (61500000516).

The spelling of 21000000504 in words is "twenty-one billion, five hundred four", and thus it is an aban number.