21311050 has 24 divisors (see below), whose sum is σ = 40092300. Its totient is φ = 8426880.

The previous prime is 21311033. The next prime is 21311051. The reversal of 21311050 is 5011312.

It can be written as a sum of positive squares in 6 ways, for example, as 998001 + 20313049 = 999^2 + 4507^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21311050.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311051) 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 11 ways as a sum of consecutive naturals, for example, 2056 + ... + 6844.

Almost surely, 2^21311050 is an apocalyptic number.

21311050 is a deficient number, since it is larger than the sum of its proper divisors (18781250).

21311050 is a wasteful number, since it uses less digits than its factorization.

21311050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4890 (or 4885 counting only the distinct ones).

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 21311050 is about 4616.3892816789. The cubic root of 21311050 is about 277.2479110965.

Adding to 21311050 its reverse (5011312), we get a palindrome (26322362).

The spelling of 21311050 in words is "twenty-one million, three hundred eleven thousand, fifty".