21516093 has 12 divisors (see below), whose sum is σ = 31505500. Its totient is φ = 14147136.

The previous prime is 21516071. The next prime is 21516119. The reversal of 21516093 is 39061512.

21516093 is a `hidden beast` number, since 2 + 1 + 51 + 609 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8749764 + 12766329 = 2958^2 + 3573^2 .

It is not a de Polignac number, because 21516093 - 2⁶ = 21516029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21516193) 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, 15718 + ... + 17031.

Almost surely, 2^21516093 is an apocalyptic number.

It is an amenable number.

21516093 is a deficient number, since it is larger than the sum of its proper divisors (9989407).

21516093 is a wasteful number, since it uses less digits than its factorization.

21516093 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32828 (or 32825 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 21516093 is about 4638.5442759556. The cubic root of 21516093 is about 278.1342492905.

The spelling of 21516093 in words is "twenty-one million, five hundred sixteen thousand, ninety-three".