20021023 has 6 divisors (see below), whose sum is σ = 22006712. Its totient is φ = 18200820.

The previous prime is 20021021. The next prime is 20021059. The reversal of 20021023 is 32012002.

It is not a de Polignac number, because 20021023 - 2¹ = 20021021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021021) 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, 82611 + ... + 82852.

Almost surely, 2^20021023 is an apocalyptic number.

20021023 is a deficient number, since it is larger than the sum of its proper divisors (1985689).

20021023 is a wasteful number, since it uses less digits than its factorization.

20021023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165485 (or 165474 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 20021023 is about 4474.4857805115. The cubic root of 20021023 is about 271.5368370237.

Adding to 20021023 its reverse (32012002), we get a palindrome (52033025).

It can be divided in two parts, 2002 and 1023, that added together give a square (3025 = 55²).

The spelling of 20021023 in words is "twenty million, twenty-one thousand, twenty-three".