21343664 has 20 divisors (see below), whose sum is σ = 41459400. Its totient is φ = 10644480.

The previous prime is 21343661. The next prime is 21343691. The reversal of 21343664 is 46634312.

It is not an unprimeable number, because it can be changed into a prime (21343661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5699 + ... + 8669.

It is an arithmetic number, because the mean of its divisors is an integer number (2072970).

Almost surely, 2^21343664 is an apocalyptic number.

It is an amenable number.

21343664 is a deficient number, since it is larger than the sum of its proper divisors (20115736).

21343664 is a wasteful number, since it uses less digits than its factorization.

21343664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3428 (or 3422 counting only the distinct ones).

The product of its digits is 10368, while the sum is 29.

The square root of 21343664 is about 4619.9203456337. The cubic root of 21343664 is about 277.3892705422.

Adding to 21343664 its reverse (46634312), we get a palindrome (67977976).

The spelling of 21343664 in words is "twenty-one million, three hundred forty-three thousand, six hundred sixty-four".