20345251 has 2 divisors, whose sum is σ = 20345252. Its totient is φ = 20345250.

The previous prime is 20345249. The next prime is 20345261. The reversal of 20345251 is 15254302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20345251 - 2¹ = 20345249 is a prime.

Together with 20345249, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20345231) 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, 10172625 + 10172626.

It is an arithmetic number, because the mean of its divisors is an integer number (10172626).

Almost surely, 2^20345251 is an apocalyptic number.

20345251 is a deficient number, since it is larger than the sum of its proper divisors (1).

20345251 is an equidigital number, since it uses as much as digits as its factorization.

20345251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 20345251 is about 4510.5710281515. The cubic root of 20345251 is about 272.9947849281.

Adding to 20345251 its reverse (15254302), we get a palindrome (35599553).

It can be divided in two parts, 203 and 45251, that added together give a palindrome (45454).

The spelling of 20345251 in words is "twenty million, three hundred forty-five thousand, two hundred fifty-one".