21000264 has 16 divisors (see below), whose sum is σ = 52500720. Its totient is φ = 7000080.

The previous prime is 21000251. The next prime is 21000269. The reversal of 21000264 is 46200012.

It is a super-2 number, since 2×21000264² = 882022176139392, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21000269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 437482 + ... + 437529.

It is an arithmetic number, because the mean of its divisors is an integer number (3281295).

Almost surely, 2^21000264 is an apocalyptic number.

21000264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21000264 is an abundant number, since it is smaller than the sum of its proper divisors (31500456).

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

21000264 is a wasteful number, since it uses less digits than its factorization.

21000264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 875020 (or 875016 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21000264 is about 4582.6044996268. The cubic root of 21000264 is about 275.8935737539.

Adding to 21000264 its reverse (46200012), we get a palindrome (67200276).

The spelling of 21000264 in words is "twenty-one million, two hundred sixty-four", and thus it is an aban number.