21264075 has 72 divisors (see below), whose sum is σ = 45497088. Its totient is φ = 9282240.

The previous prime is 21264073. The next prime is 21264079. The reversal of 21264075 is 57046212.

21264075 is a `hidden beast` number, since 2 + 12 + 640 + 7 + 5 = 666.

It is not a de Polignac number, because 21264075 - 2¹ = 21264073 is a prime.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (21264071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 35932 + ... + 36518.

It is an arithmetic number, because the mean of its divisors is an integer number (631904).

Almost surely, 2^21264075 is an apocalyptic number.

21264075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21264075 is an abundant number, since it is smaller than the sum of its proper divisors (24233013).

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

21264075 is a wasteful number, since it uses less digits than its factorization.

21264075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 633 (or 625 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 21264075 is about 4611.2986240321. The cubic root of 21264075 is about 277.0440528233.

The spelling of 21264075 in words is "twenty-one million, two hundred sixty-four thousand, seventy-five".