20305431 has 8 divisors (see below), whose sum is σ = 30082160. Its totient is φ = 13536936.

The previous prime is 20305427. The next prime is 20305451. The reversal of 20305431 is 13450302.

It is not a de Polignac number, because 20305431 - 2² = 20305427 is a prime.

It is a super-2 number, since 2×20305431² = 824621056191522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20305421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 376000 + ... + 376053.

It is an arithmetic number, because the mean of its divisors is an integer number (3760270).

Almost surely, 2^20305431 is an apocalyptic number.

20305431 is a deficient number, since it is larger than the sum of its proper divisors (9776729).

20305431 is an equidigital number, since it uses as much as digits as its factorization.

20305431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752062 (or 752056 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 20305431 is about 4506.1547909498. The cubic root of 20305431 is about 272.8165655799.

Adding to 20305431 its reverse (13450302), we get a palindrome (33755733).

It can be divided in two parts, 20305 and 431, that added together give a 4-th power (20736 = 12⁴).

The spelling of 20305431 in words is "twenty million, three hundred five thousand, four hundred thirty-one".