21316480 has 64 divisors (see below), whose sum is σ = 53672400. Its totient is φ = 8073216.

The previous prime is 21316459. The next prime is 21316481. The reversal of 21316480 is 8461312.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21316481) 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, 11284 + ... + 13036.

Almost surely, 2^21316480 is an apocalyptic number.

21316480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21316480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26836200).

21316480 is an abundant number, since it is smaller than the sum of its proper divisors (32355920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21316480 is a wasteful number, since it uses less digits than its factorization.

21316480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1791 (or 1779 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 21316480 is about 4616.9773661997. The cubic root of 21316480 is about 277.2714564453.

Adding to 21316480 its reverse (8461312), we get a palindrome (29777792).

The spelling of 21316480 in words is "twenty-one million, three hundred sixteen thousand, four hundred eighty".