20021003 has 4 divisors (see below), whose sum is σ = 21074760. Its totient is φ = 18967248.

The previous prime is 20020943. The next prime is 20021021. The reversal of 20021003 is 30012002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20021003 - 2¹² = 20016907 is a prime.

It is a super-2 number, since 2×20021003² = 801681122252018, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021093) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 526850 + ... + 526887.

It is an arithmetic number, because the mean of its divisors is an integer number (5268690).

Almost surely, 2^20021003 is an apocalyptic number.

20021003 is a deficient number, since it is larger than the sum of its proper divisors (1053757).

20021003 is a wasteful number, since it uses less digits than its factorization.

20021003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1053756.

The product of its (nonzero) digits is 12, while the sum is 8.

The square root of 20021003 is about 4474.4835456173. The cubic root of 20021003 is about 271.5367466064.

Adding to 20021003 its reverse (30012002), we get a palindrome (50033005).

Subtracting 20021003 from its reverse (30012002), we obtain a palindrome (9990999).

The spelling of 20021003 in words is "twenty million, twenty-one thousand, three".