21416634 has 72 divisors (see below), whose sum is σ = 51723360. Its totient is φ = 6390912.

The previous prime is 21416609. The next prime is 21416641. The reversal of 21416634 is 43661412.

21416634 is a `hidden beast` number, since 2 + 14 + 16 + 634 = 666.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21416598 and 21416607.

It is a congruent number.

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 35 ways as a sum of consecutive naturals, for example, 119557 + ... + 119735.

It is an arithmetic number, because the mean of its divisors is an integer number (718380).

Almost surely, 2^21416634 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21416634, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25861680).

21416634 is an abundant number, since it is smaller than the sum of its proper divisors (30306726).

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

21416634 is a wasteful number, since it uses less digits than its factorization.

21416634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 224 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 21416634 is about 4627.8109295865. The cubic root of 21416634 is about 277.7050250122.

The spelling of 21416634 in words is "twenty-one million, four hundred sixteen thousand, six hundred thirty-four".