21340575 has 18 divisors (see below), whose sum is σ = 38223744. Its totient is φ = 11381520.

The previous prime is 21340567. The next prime is 21340597. The reversal of 21340575 is 57504312.

It is a happy number.

It is not a de Polignac number, because 21340575 - 2³ = 21340567 is a prime.

It is a congruent number.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 47199 + ... + 47648.

Almost surely, 2^21340575 is an apocalyptic number.

21340575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21340575 is a deficient number, since it is larger than the sum of its proper divisors (16883169).

21340575 is a wasteful number, since it uses less digits than its factorization.

21340575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94863 (or 94855 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 21340575 is about 4619.5860204135. The cubic root of 21340575 is about 277.3758880102.

Adding to 21340575 its reverse (57504312), we get a palindrome (78844887).

The spelling of 21340575 in words is "twenty-one million, three hundred forty thousand, five hundred seventy-five".