21050003 has 16 divisors (see below), whose sum is σ = 23556960. Its totient is φ = 18683136.

The previous prime is 21049949. The next prime is 21050011. The reversal of 21050003 is 30005012.

It is a cyclic number.

It is not a de Polignac number, because 21050003 - 2⁶ = 21049939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21050033) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51263 + ... + 51671.

It is an arithmetic number, because the mean of its divisors is an integer number (1472310).

Almost surely, 2^21050003 is an apocalyptic number.

21050003 is a deficient number, since it is larger than the sum of its proper divisors (2506957).

21050003 is a wasteful number, since it uses less digits than its factorization.

21050003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566.

The product of its (nonzero) digits is 30, while the sum is 11.

The square root of 21050003 is about 4588.0282257196. The cubic root of 21050003 is about 276.1112194412. Note that the first 3 decimals are identical.

Adding to 21050003 its reverse (30005012), we get a palindrome (51055015).

The spelling of 21050003 in words is "twenty-one million, fifty thousand, three".