21986792784 has 240 divisors, whose sum is σ = 71380056384. Its totient is φ = 6243840000.

The previous prime is 21986792759. The next prime is 21986792819. The reversal of 21986792784 is 48729768912.

21986792784 is a `hidden beast` number, since 219 + 86 + 79 + 278 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6757302 + ... + 6760554.

Almost surely, 2^21986792784 is an apocalyptic number.

21986792784 is a gapful number since it is divisible by the number (24) 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 21986792784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35690028192).

21986792784 is an abundant number, since it is smaller than the sum of its proper divisors (49393263600).

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

21986792784 is a wasteful number, since it uses less digits than its factorization.

21986792784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3546 (or 3537 counting only the distinct ones).

The product of its digits is 24385536, while the sum is 63.

The spelling of 21986792784 in words is "twenty-one billion, nine hundred eighty-six million, seven hundred ninety-two thousand, seven hundred eighty-four".