21265575 has 12 divisors (see below), whose sum is σ = 35159208. Its totient is φ = 11341600.

The previous prime is 21265553. The next prime is 21265577. The reversal of 21265575 is 57556212.

It is not a de Polignac number, because 21265575 - 2¹⁴ = 21249191 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21265577) 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 11 ways as a sum of consecutive naturals, for example, 141696 + ... + 141845.

It is an arithmetic number, because the mean of its divisors is an integer number (2929934).

Almost surely, 2^21265575 is an apocalyptic number.

21265575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21265575 is a deficient number, since it is larger than the sum of its proper divisors (13893633).

21265575 is a wasteful number, since it uses less digits than its factorization.

21265575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283554 (or 283549 counting only the distinct ones).

The product of its digits is 21000, while the sum is 33.

The square root of 21265575 is about 4611.4612651523. The cubic root of 21265575 is about 277.0505670389.

The spelling of 21265575 in words is "twenty-one million, two hundred sixty-five thousand, five hundred seventy-five".