21516485 has 8 divisors (see below), whose sum is σ = 25867296. Its totient is φ = 17181520.

The previous prime is 21516437. The next prime is 21516487. The reversal of 21516485 is 58461512.

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

It is not a de Polignac number, because 21516485 - 2⁶ = 21516421 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 (21516487) 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, 731 + ... + 6600.

It is an arithmetic number, because the mean of its divisors is an integer number (3233412).

Almost surely, 2^21516485 is an apocalyptic number.

It is an amenable number.

21516485 is a deficient number, since it is larger than the sum of its proper divisors (4350811).

21516485 is an equidigital number, since it uses as much as digits as its factorization.

21516485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7923.

The product of its digits is 9600, while the sum is 32.

The square root of 21516485 is about 4638.5865303991. The cubic root of 21516485 is about 278.1359383822.

Adding to 21516485 its reverse (58461512), we get a palindrome (79977997).

The spelling of 21516485 in words is "twenty-one million, five hundred sixteen thousand, four hundred eighty-five".