21344634 has 48 divisors (see below), whose sum is σ = 49297248. Its totient is φ = 6916752.

The previous prime is 21344629. The next prime is 21344663. The reversal of 21344634 is 43644312.

21344634 is a `hidden beast` number, since 21 + 3 + 4 + 4 + 634 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21344598 and 21344607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17389 + ... + 18575.

It is an arithmetic number, because the mean of its divisors is an integer number (1027026).

Almost surely, 2^21344634 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21344634, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24648624).

21344634 is an abundant number, since it is smaller than the sum of its proper divisors (27952614).

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

21344634 is a wasteful number, since it uses less digits than its factorization.

21344634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241 (or 1229 counting only the distinct ones).

The product of its digits is 6912, while the sum is 27.

The square root of 21344634 is about 4620.0253246059. The cubic root of 21344634 is about 277.3934726248.

Adding to 21344634 its reverse (43644312), we get a palindrome (64988946).

The spelling of 21344634 in words is "twenty-one million, three hundred forty-four thousand, six hundred thirty-four".