21116503800 has 576 divisors, whose sum is σ = 83649646080. Its totient is φ = 4674309120.

The previous prime is 21116503799. The next prime is 21116503801. The reversal of 21116503800 is 830561112.

21116503800 is a `hidden beast` number, since 2 + 1 + 1 + 1 + 650 + 3 + 8 + 0 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21116503799) and next prime (21116503801).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21116503801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 68783247 + ... + 68783553.

It is an arithmetic number, because the mean of its divisors is an integer number (145225080).

Almost surely, 2^21116503800 is an apocalyptic number.

21116503800 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 21116503800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41824823040).

21116503800 is an abundant number, since it is smaller than the sum of its proper divisors (62533142280).

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

21116503800 is a wasteful number, since it uses less digits than its factorization.

21116503800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492 (or 480 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 21116503800 in words is "twenty-one billion, one hundred sixteen million, five hundred three thousand, eight hundred".