21783879936 has 576 divisors, whose sum is σ = 80765798400. Its totient is φ = 5638201344.

The previous prime is 21783879847. The next prime is 21783879947. The reversal of 21783879936 is 63997838712.

21783879936 is a `hidden beast` number, since 217 + 8 + 387 + 9 + 9 + 36 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-3 number, since 3×21783879936³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 37110235 + ... + 37110821.

It is an arithmetic number, because the mean of its divisors is an integer number (140218400).

Almost surely, 2^21783879936 is an apocalyptic number.

21783879936 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 21783879936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40382899200).

21783879936 is an abundant number, since it is smaller than the sum of its proper divisors (58981918464).

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

21783879936 is a wasteful number, since it uses less digits than its factorization.

21783879936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691 (or 671 counting only the distinct ones).

The product of its digits is 27433728, while the sum is 63.

The spelling of 21783879936 in words is "twenty-one billion, seven hundred eighty-three million, eight hundred seventy-nine thousand, nine hundred thirty-six".