21000050 has 12 divisors (see below), whose sum is σ = 39060186. Its totient is φ = 8400000.

The previous prime is 21000041. The next prime is 21000059. The reversal of 21000050 is 5000012.

It is an interprime number because it is at equal distance from previous prime (21000041) and next prime (21000059).

It can be written as a sum of positive squares in 3 ways, for example, as 17581249 + 3418801 = 4193^2 + 1849^2 .

It is not an unprimeable number, because it can be changed into a prime (21000059) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 209951 + ... + 210050.

Almost surely, 2^21000050 is an apocalyptic number.

21000050 is a deficient number, since it is larger than the sum of its proper divisors (18060136).

21000050 is a wasteful number, since it uses less digits than its factorization.

21000050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420013 (or 420008 counting only the distinct ones).

The product of its (nonzero) digits is 10, while the sum is 8.

The square root of 21000050 is about 4582.5811503998. The cubic root of 21000050 is about 275.8926366002.

Adding to 21000050 its reverse (5000012), we get a palindrome (26000062).

The spelling of 21000050 in words is "twenty-one million, fifty", and thus it is an aban number and an uban number.