21743634 has 32 divisors (see below), whose sum is σ = 48101184. Its totient is φ = 6497280.

The previous prime is 21743627. The next prime is 21743639. The reversal of 21743634 is 43634712.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21743639) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2562 + ... + 7074.

It is an arithmetic number, because the mean of its divisors is an integer number (1503162).

Almost surely, 2^21743634 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21743634, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24050592).

21743634 is an abundant number, since it is smaller than the sum of its proper divisors (26357550).

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

21743634 is a wasteful number, since it uses less digits than its factorization.

21743634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4602.

The product of its digits is 12096, while the sum is 30.

The square root of 21743634 is about 4663.0069697567. The cubic root of 21743634 is about 279.1112722742. Note that the first 3 decimals are identical.

It can be divided in two parts, 217436 and 34, that added together give a triangular number (217470 = T₆₅₉).

The spelling of 21743634 in words is "twenty-one million, seven hundred forty-three thousand, six hundred thirty-four".