21366000500 has 48 divisors (see below), whose sum is σ = 50252848464. Its totient is φ = 7888982400.

The previous prime is 21366000499. The next prime is 21366000511. The reversal of 21366000500 is 500066312.

It can be written as a sum of positive squares in 8 ways, for example, as 9718410724 + 11647589776 = 98582^2 + 107924^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1637039 + ... + 1650038.

It is an arithmetic number, because the mean of its divisors is an integer number (1046934343).

Almost surely, 2^21366000500 is an apocalyptic number.

21366000500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21366000500 is an abundant number, since it is smaller than the sum of its proper divisors (28886847964).

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

21366000500 is a wasteful number, since it uses less digits than its factorization.

21366000500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3287109 (or 3287097 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 23.

Adding to 21366000500 its reverse (500066312), we get a palindrome (21866066812).

The spelling of 21366000500 in words is "twenty-one billion, three hundred sixty-six million, five hundred", and thus it is an aban number.