21734856 has 96 divisors (see below), whose sum is σ = 69189120. Its totient is φ = 6076800.

The previous prime is 21734851. The next prime is 21734863. The reversal of 21734856 is 65843712.

21734856 is a `hidden beast` number, since 2 + 173 + 485 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21734856.

It is not an unprimeable number, because it can be changed into a prime (21734851) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9241 + ... + 11351.

It is an arithmetic number, because the mean of its divisors is an integer number (720720).

Almost surely, 2^21734856 is an apocalyptic number.

21734856 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 21734856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34594560).

21734856 is an abundant number, since it is smaller than the sum of its proper divisors (47454264).

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

21734856 is a wasteful number, since it uses less digits than its factorization.

21734856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2147 (or 2140 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 21734856 is about 4662.0656366036. The cubic root of 21734856 is about 279.0737077389.

The spelling of 21734856 in words is "twenty-one million, seven hundred thirty-four thousand, eight hundred fifty-six".