21260316 has 144 divisors (see below), whose sum is σ = 66648960. Its totient is φ = 5201280.

The previous prime is 21260299. The next prime is 21260321. The reversal of 21260316 is 61306212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 21260292 and 21260301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 122806 + ... + 122978.

It is an arithmetic number, because the mean of its divisors is an integer number (462840).

Almost surely, 2^21260316 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21260316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33324480).

21260316 is an abundant number, since it is smaller than the sum of its proper divisors (45388644).

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

21260316 is a wasteful number, since it uses less digits than its factorization.

21260316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21260316 is about 4610.8910201825. The cubic root of 21260316 is about 277.0277268531.

Adding to 21260316 its reverse (61306212), we get a palindrome (82566528).

The spelling of 21260316 in words is "twenty-one million, two hundred sixty thousand, three hundred sixteen".