20021253 has 16 divisors (see below), whose sum is σ = 31132800. Its totient is φ = 11440128.

The previous prime is 20021251. The next prime is 20021263. The reversal of 20021253 is 35212002.

It is not a de Polignac number, because 20021253 - 2¹ = 20021251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8700 + ... + 10757.

It is an arithmetic number, because the mean of its divisors is an integer number (1945800).

Almost surely, 2^20021253 is an apocalyptic number.

It is an amenable number.

20021253 is a deficient number, since it is larger than the sum of its proper divisors (11111547).

20021253 is an equidigital number, since it uses as much as digits as its factorization.

20021253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19481 (or 19467 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 20021253 is about 4474.5114817151. The cubic root of 20021253 is about 271.5378768179.

Adding to 20021253 its reverse (35212002), we get a palindrome (55233255).

The spelling of 20021253 in words is "twenty million, twenty-one thousand, two hundred fifty-three".