21020264 has 16 divisors (see below), whose sum is σ = 39463200. Its totient is φ = 10496752.

The previous prime is 21020239. The next prime is 21020267. The reversal of 21020264 is 46202012.

It is not an unprimeable number, because it can be changed into a prime (21020267) 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 in 3 ways as a sum of consecutive naturals, for example, 9029 + ... + 11115.

It is an arithmetic number, because the mean of its divisors is an integer number (2466450).

Almost surely, 2^21020264 is an apocalyptic number.

It is an amenable number.

21020264 is a deficient number, since it is larger than the sum of its proper divisors (18442936).

21020264 is a wasteful number, since it uses less digits than its factorization.

21020264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3352 (or 3348 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21020264 is about 4584.7861455034. The cubic root of 21020264 is about 275.9811301249.

Adding to 21020264 its reverse (46202012), we get a palindrome (67222276).

The spelling of 21020264 in words is "twenty-one million, twenty thousand, two hundred sixty-four".