21050316 has 72 divisors (see below), whose sum is σ = 61478144. Its totient is φ = 5948640.

The previous prime is 21050311. The next prime is 21050339. The reversal of 21050316 is 61305012.

21050316 is a nontrivial binomial coefficient, being equal to C(6489, 2).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21050311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25551 + ... + 26361.

Almost surely, 2^21050316 is an apocalyptic number.

21050316 is the 6488-th triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21050316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30739072).

21050316 is an abundant number, since it is smaller than the sum of its proper divisors (40427828).

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

21050316 is a wasteful number, since it uses less digits than its factorization.

21050316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931 (or 926 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 21050316 is about 4588.0623361066. The cubic root of 21050316 is about 276.1125879665.

Adding to 21050316 its reverse (61305012), we get a palindrome (82355328).

The spelling of 21050316 in words is "twenty-one million, fifty thousand, three hundred sixteen".