21234664 has 16 divisors (see below), whose sum is σ = 43434720. Its totient is φ = 9652080.

The previous prime is 21234623. The next prime is 21234667. The reversal of 21234664 is 46643212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234667) 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, 120564 + ... + 120739.

It is an arithmetic number, because the mean of its divisors is an integer number (2714670).

Almost surely, 2^21234664 is an apocalyptic number.

It is an amenable number.

21234664 is an abundant number, since it is smaller than the sum of its proper divisors (22200056).

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

21234664 is a wasteful number, since it uses less digits than its factorization.

21234664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241320 (or 241316 counting only the distinct ones).

The product of its digits is 6912, while the sum is 28.

The square root of 21234664 is about 4608.1085056669. The cubic root of 21234664 is about 276.9162644889.

Adding to 21234664 its reverse (46643212), we get a palindrome (67877876).

The spelling of 21234664 in words is "twenty-one million, two hundred thirty-four thousand, six hundred sixty-four".