21017264 has 10 divisors (see below), whose sum is σ = 40720980. Its totient is φ = 10508624.

The previous prime is 21017233. The next prime is 21017273. The reversal of 21017264 is 46271012.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656774 + ... + 656805.

It is an arithmetic number, because the mean of its divisors is an integer number (4072098).

Almost surely, 2^21017264 is an apocalyptic number.

It is an amenable number.

21017264 is a deficient number, since it is larger than the sum of its proper divisors (19703716).

21017264 is a wasteful number, since it uses less digits than its factorization.

21017264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1313587 (or 1313581 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21017264 is about 4584.4589648071. The cubic root of 21017264 is about 275.9680002108.

Adding to 21017264 its reverse (46271012), we get a palindrome (67288276).

The spelling of 21017264 in words is "twenty-one million, seventeen thousand, two hundred sixty-four".