21116583 has 12 divisors (see below), whose sum is σ = 31151328. Its totient is φ = 13777920.

The previous prime is 21116561. The next prime is 21116587. The reversal of 21116583 is 38561112.

21116583 is a `hidden beast` number, since 2 + 1 + 1 + 1 + 658 + 3 = 666.

It is not a de Polignac number, because 21116583 - 2⁶ = 21116519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21116587) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24538 + ... + 25383.

It is an arithmetic number, because the mean of its divisors is an integer number (2595944).

Almost surely, 2^21116583 is an apocalyptic number.

21116583 is a deficient number, since it is larger than the sum of its proper divisors (10034745).

21116583 is a wasteful number, since it uses less digits than its factorization.

21116583 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49974 (or 49971 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 21116583 is about 4595.2783375983. The cubic root of 21116583 is about 276.4020212524.

Adding to 21116583 its reverse (38561112), we get a palindrome (59677695).

The spelling of 21116583 in words is "twenty-one million, one hundred sixteen thousand, five hundred eighty-three".