21034664 has 32 divisors (see below), whose sum is σ = 45532800. Its totient is φ = 8923200.

The previous prime is 21034613. The next prime is 21034667. The reversal of 21034664 is 46643012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21034667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3797 + ... + 7515.

It is an arithmetic number, because the mean of its divisors is an integer number (1422900).

Almost surely, 2^21034664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21034664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22766400).

21034664 is an abundant number, since it is smaller than the sum of its proper divisors (24498136).

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

21034664 is a wasteful number, since it uses less digits than its factorization.

21034664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3833 (or 3829 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 21034664 is about 4586.3562879480. The cubic root of 21034664 is about 276.0441363288.

Adding to 21034664 its reverse (46643012), we get a palindrome (67677676).

The spelling of 21034664 in words is "twenty-one million, thirty-four thousand, six hundred sixty-four".