20533431 has 4 divisors (see below), whose sum is σ = 27377912. Its totient is φ = 13688952.

The previous prime is 20533427. The next prime is 20533451. The reversal of 20533431 is 13433502.

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

It is not a de Polignac number, because 20533431 - 2² = 20533427 is a prime.

It is a super-2 number, since 2×20533431² = 843243577263522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20533398 and 20533407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20533451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3422236 + ... + 3422241.

It is an arithmetic number, because the mean of its divisors is an integer number (6844478).

Almost surely, 2^20533431 is an apocalyptic number.

20533431 is a deficient number, since it is larger than the sum of its proper divisors (6844481).

20533431 is an equidigital number, since it uses as much as digits as its factorization.

20533431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6844480.

The product of its (nonzero) digits is 1080, while the sum is 21.

The square root of 20533431 is about 4531.3829014993. The cubic root of 20533431 is about 273.8338764266.

Adding to 20533431 its reverse (13433502), we get a palindrome (33966933).

The spelling of 20533431 in words is "twenty million, five hundred thirty-three thousand, four hundred thirty-one".