21117532 has 12 divisors (see below), whose sum is σ = 37653336. Its totient is φ = 10359440.

The previous prime is 21117521. The next prime is 21117557. The reversal of 21117532 is 23571112.

It is a happy number.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 49594 + ... + 50017.

It is an arithmetic number, because the mean of its divisors is an integer number (3137778).

Almost surely, 2^21117532 is an apocalyptic number.

It is an amenable number.

21117532 is a deficient number, since it is larger than the sum of its proper divisors (16535804).

21117532 is a wasteful number, since it uses less digits than its factorization.

21117532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99668 (or 99666 counting only the distinct ones).

The product of its digits is 420, while the sum is 22.

The square root of 21117532 is about 4595.3815946013. The cubic root of 21117532 is about 276.4061617832.

Adding to 21117532 its reverse (23571112), we get a palindrome (44688644).

The spelling of 21117532 in words is "twenty-one million, one hundred seventeen thousand, five hundred thirty-two".