20426431 has 4 divisors (see below), whose sum is σ = 20435472. Its totient is φ = 20417392.

The previous prime is 20426429. The next prime is 20426443. The reversal of 20426431 is 13462402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20426431 - 2¹ = 20426429 is a prime.

It is a super-2 number, since 2×20426431² = 834478166795522, 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 (20426831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2166 + ... + 6748.

It is an arithmetic number, because the mean of its divisors is an integer number (5108868).

Almost surely, 2^20426431 is an apocalyptic number.

20426431 is a deficient number, since it is larger than the sum of its proper divisors (9041).

20426431 is an equidigital number, since it uses as much as digits as its factorization.

20426431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9040.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 20426431 is about 4519.5609300019. The cubic root of 20426431 is about 273.3573970816.

Adding to 20426431 its reverse (13462402), we get a palindrome (33888833).

The spelling of 20426431 in words is "twenty million, four hundred twenty-six thousand, four hundred thirty-one".