21112516 has 12 divisors (see below), whose sum is σ = 36985788. Its totient is φ = 10545152.

The previous prime is 21112433. The next prime is 21112547. The reversal of 21112516 is 61521112.

It can be written as a sum of positive squares in 2 ways, for example, as 2656900 + 18455616 = 1630^2 + 4296^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21112493 and 21112502.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2700 + ... + 7036.

It is an arithmetic number, because the mean of its divisors is an integer number (3082149).

Almost surely, 2^21112516 is an apocalyptic number.

It is an amenable number.

21112516 is a deficient number, since it is larger than the sum of its proper divisors (15873272).

21112516 is a wasteful number, since it uses less digits than its factorization.

21112516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5558 (or 5556 counting only the distinct ones).

The product of its digits is 120, while the sum is 19.

The square root of 21112516 is about 4594.8357968485. The cubic root of 21112516 is about 276.3842753384.

Adding to 21112516 its reverse (61521112), we get a palindrome (82633628).

The spelling of 21112516 in words is "twenty-one million, one hundred twelve thousand, five hundred sixteen".