20523431 has 2 divisors, whose sum is σ = 20523432. Its totient is φ = 20523430.

The previous prime is 20523421. The next prime is 20523449. The reversal of 20523431 is 13432502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20523431 - 2¹⁸ = 20261287 is a prime.

It is a super-2 number, since 2×20523431² = 842422440023522, 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 (20523421) 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 as a sum of consecutive naturals, namely, 10261715 + 10261716.

It is an arithmetic number, because the mean of its divisors is an integer number (10261716).

Almost surely, 2^20523431 is an apocalyptic number.

20523431 is a deficient number, since it is larger than the sum of its proper divisors (1).

20523431 is an equidigital number, since it uses as much as digits as its factorization.

20523431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 20523431 is about 4530.2793512100. The cubic root of 20523431 is about 273.7894158683.

Adding to 20523431 its reverse (13432502), we get a palindrome (33955933).

The spelling of 20523431 in words is "twenty million, five hundred twenty-three thousand, four hundred thirty-one".