20440431 has 28 divisors (see below), whose sum is σ = 33445800. Its totient is φ = 12383280.

The previous prime is 20440423. The next prime is 20440487. The reversal of 20440431 is 13404402.

It is not a de Polignac number, because 20440431 - 2³ = 20440423 is a prime.

It is a super-2 number, since 2×20440431² = 835622438931522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20440421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 6745 + ... + 9293.

Almost surely, 2^20440431 is an apocalyptic number.

20440431 is a deficient number, since it is larger than the sum of its proper divisors (13005369).

20440431 is an equidigital number, since it uses as much as digits as its factorization.

20440431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2578 (or 2563 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 20440431 is about 4521.1094877253. The cubic root of 20440431 is about 273.4198346422.

Adding to 20440431 its reverse (13404402), we get a palindrome (33844833).

The spelling of 20440431 in words is "twenty million, four hundred forty thousand, four hundred thirty-one".