21116481 has 8 divisors (see below), whose sum is σ = 28220640. Its totient is φ = 14044992.

The previous prime is 21116479. The next prime is 21116503. The reversal of 21116481 is 18461112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21116481 - 2¹ = 21116479 is a prime.

It is a super-2 number, since 2×21116481² = 891811539646722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21116401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6616 + ... + 9273.

It is an arithmetic number, because the mean of its divisors is an integer number (3527580).

Almost surely, 2^21116481 is an apocalyptic number.

It is an amenable number.

21116481 is a deficient number, since it is larger than the sum of its proper divisors (7104159).

21116481 is a wasteful number, since it uses less digits than its factorization.

21116481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16335.

The product of its digits is 384, while the sum is 24.

The square root of 21116481 is about 4595.2672392365. The cubic root of 21116481 is about 276.4015762143.

Adding to 21116481 its reverse (18461112), we get a palindrome (39577593).

The spelling of 21116481 in words is "twenty-one million, one hundred sixteen thousand, four hundred eighty-one".