21843273816 has 768 divisors, whose sum is σ = 80074874880. Its totient is φ = 5225472000.

The previous prime is 21843273703. The next prime is 21843273833. The reversal of 21843273816 is 61837234812.

It is a super-2 number, since 2×21843273816² (a number of 21 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 358086426 + ... + 358086486.

It is an arithmetic number, because the mean of its divisors is an integer number (104264160).

Almost surely, 2^21843273816 is an apocalyptic number.

21843273816 is a gapful number since it is divisible by the number (26) 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 21843273816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40037437440).

21843273816 is an abundant number, since it is smaller than the sum of its proper divisors (58231601064).

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

21843273816 is a wasteful number, since it uses less digits than its factorization.

21843273816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208 (or 201 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The spelling of 21843273816 in words is "twenty-one billion, eight hundred forty-three million, two hundred seventy-three thousand, eight hundred sixteen".