21821404734 has 72 divisors (see below), whose sum is σ = 50246600040. Its totient is φ = 6825343392.

The previous prime is 21821404681. The next prime is 21821404751. The reversal of 21821404734 is 43740412812.

21821404734 is a `hidden beast` number, since 2 + 182 + 1 + 4 + 0 + 473 + 4 = 666.

It is a super-2 number, since 2×21821404734² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3912772 + ... + 3918344.

It is an arithmetic number, because the mean of its divisors is an integer number (697869445).

Almost surely, 2^21821404734 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21821404734, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25123300020).

21821404734 is an abundant number, since it is smaller than the sum of its proper divisors (28425195306).

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

21821404734 is a wasteful number, since it uses less digits than its factorization.

21821404734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5814 (or 5704 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The spelling of 21821404734 in words is "twenty-one billion, eight hundred twenty-one million, four hundred four thousand, seven hundred thirty-four".