20345231 has 2 divisors, whose sum is σ = 20345232. Its totient is φ = 20345230.

The previous prime is 20345167. The next prime is 20345233. The reversal of 20345231 is 13254302.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20345231 - 2⁶ = 20345167 is a prime.

It is a super-2 number, since 2×20345231² = 827856848886722, which contains 22 as substring.

Together with 20345233, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20345233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10172615 + 10172616.

It is an arithmetic number, because the mean of its divisors is an integer number (10172616).

Almost surely, 2^20345231 is an apocalyptic number.

20345231 is a deficient number, since it is larger than the sum of its proper divisors (1).

20345231 is an equidigital number, since it uses as much as digits as its factorization.

20345231 is an evil number, because the sum of its binary digits is even.

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

The square root of 20345231 is about 4510.5688111368. The cubic root of 20345231 is about 272.9946954740.

Adding to 20345231 its reverse (13254302), we get a palindrome (33599533).

The spelling of 20345231 in words is "twenty million, three hundred forty-five thousand, two hundred thirty-one".