21050766 has 40 divisors (see below), whose sum is σ = 51461784. Its totient is φ = 6378480.

The previous prime is 21050749. The next prime is 21050801. The reversal of 21050766 is 66705012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 4125 + ... + 7688.

Almost surely, 2^21050766 is an apocalyptic number.

21050766 is an abundant number, since it is smaller than the sum of its proper divisors (30411018).

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

21050766 is a wasteful number, since it uses less digits than its factorization.

21050766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11838 (or 11829 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 21050766 is about 4588.1113761547. Note that the first 3 decimals coincide. The cubic root of 21050766 is about 276.1145554711.

Adding to 21050766 its reverse (66705012), we get a palindrome (87755778).

The spelling of 21050766 in words is "twenty-one million, fifty thousand, seven hundred sixty-six".