21535065 has 20 divisors (see below), whose sum is σ = 38604324. Its totient is φ = 11485152.

The previous prime is 21535027. The next prime is 21535091. The reversal of 21535065 is 56053512.

21535065 is a `hidden beast` number, since 2 + 153 + 506 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 10265616 + 11269449 = 3204^2 + 3357^2 .

It is not a de Polignac number, because 21535065 - 2⁶ = 21535001 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 26182 + ... + 26991.

Almost surely, 2^21535065 is an apocalyptic number.

It is an amenable number.

21535065 is a deficient number, since it is larger than the sum of its proper divisors (17069259).

21535065 is an equidigital number, since it uses as much as digits as its factorization.

21535065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53190 (or 53181 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 21535065 is about 4640.5888634957. The cubic root of 21535065 is about 278.2159743632.

Adding to 21535065 its reverse (56053512), we get a palindrome (77588577).

The spelling of 21535065 in words is "twenty-one million, five hundred thirty-five thousand, sixty-five".