21634264 has 8 divisors (see below), whose sum is σ = 40564260. Its totient is φ = 10817128.

The previous prime is 21634259. The next prime is 21634267. The reversal of 21634264 is 46243612.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21634267) 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 as a sum of consecutive naturals, namely, 1352134 + ... + 1352149.

Almost surely, 2^21634264 is an apocalyptic number.

It is an amenable number.

21634264 is a deficient number, since it is larger than the sum of its proper divisors (18929996).

21634264 is a wasteful number, since it uses less digits than its factorization.

21634264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2704289 (or 2704285 counting only the distinct ones).

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

The square root of 21634264 is about 4651.2647742308. The cubic root of 21634264 is about 278.6425109235.

Adding to 21634264 its reverse (46243612), we get a palindrome (67877876).

The spelling of 21634264 in words is "twenty-one million, six hundred thirty-four thousand, two hundred sixty-four".