20403431 has 2 divisors, whose sum is σ = 20403432. Its totient is φ = 20403430.

The previous prime is 20403419. The next prime is 20403469. The reversal of 20403431 is 13430402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20403431 - 2⁶ = 20403367 is a prime.

It is a super-2 number, since 2×20403431² = 832599993143522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20403401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10201715 + 10201716.

It is an arithmetic number, because the mean of its divisors is an integer number (10201716).

Almost surely, 2^20403431 is an apocalyptic number.

20403431 is a deficient number, since it is larger than the sum of its proper divisors (1).

20403431 is an equidigital number, since it uses as much as digits as its factorization.

20403431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 20403431 is about 4517.0157183698. The cubic root of 20403431 is about 273.2547591253.

Adding to 20403431 its reverse (13430402), we get a palindrome (33833833).

The spelling of 20403431 in words is "twenty million, four hundred three thousand, four hundred thirty-one".