20390533 has 4 divisors (see below), whose sum is σ = 20512800. Its totient is φ = 20268268.

The previous prime is 20390483. The next prime is 20390549. The reversal of 20390533 is 33509302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20390533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20390498 and 20390507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20390333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60883 + ... + 61216.

It is an arithmetic number, because the mean of its divisors is an integer number (5128200).

Almost surely, 2^20390533 is an apocalyptic number.

It is an amenable number.

20390533 is a deficient number, since it is larger than the sum of its proper divisors (122267).

20390533 is a wasteful number, since it uses less digits than its factorization.

20390533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122266.

The product of its (nonzero) digits is 2430, while the sum is 25.

The square root of 20390533 is about 4515.5877801234. The cubic root of 20390533 is about 273.1971677852.

Adding to 20390533 its reverse (33509302), we get a palindrome (53899835).

The spelling of 20390533 in words is "twenty million, three hundred ninety thousand, five hundred thirty-three".