21706264 has 8 divisors (see below), whose sum is σ = 40699260. Its totient is φ = 10853128.

The previous prime is 21706259. The next prime is 21706313. The reversal of 21706264 is 46260712.

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 an unprimeable number.

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, 1356634 + ... + 1356649.

Almost surely, 2^21706264 is an apocalyptic number.

It is an amenable number.

21706264 is a deficient number, since it is larger than the sum of its proper divisors (18992996).

21706264 is a wasteful number, since it uses less digits than its factorization.

21706264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2713289 (or 2713285 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 21706264 is about 4658.9981755738. The cubic root of 21706264 is about 278.9512810878.

Adding to 21706264 its reverse (46260712), we get a palindrome (67966976).

The spelling of 21706264 in words is "twenty-one million, seven hundred six thousand, two hundred sixty-four".