21216050 has 24 divisors (see below), whose sum is σ = 39668592. Its totient is φ = 8442000.

The previous prime is 21216047. The next prime is 21216053. The reversal of 21216050 is 5061212.

It is an interprime number because it is at equal distance from previous prime (21216047) and next prime (21216053).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21216053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9545 + ... + 11555.

It is an arithmetic number, because the mean of its divisors is an integer number (1652858).

Almost surely, 2^21216050 is an apocalyptic number.

21216050 is a deficient number, since it is larger than the sum of its proper divisors (18452542).

21216050 is a wasteful number, since it uses less digits than its factorization.

21216050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2234 (or 2229 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21216050 is about 4606.0883621572. The cubic root of 21216050 is about 276.8353272345.

Adding to 21216050 its reverse (5061212), we get a palindrome (26277262).

The spelling of 21216050 in words is "twenty-one million, two hundred sixteen thousand, fifty".