20427257 has 2 divisors, whose sum is σ = 20427258. Its totient is φ = 20427256.

The previous prime is 20427247. The next prime is 20427271. The reversal of 20427257 is 75272402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19219456 + 1207801 = 4384^2 + 1099^2 .

It is a cyclic number.

It is not a de Polignac number, because 20427257 - 2⁴ = 20427241 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20427247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10213628 + 10213629.

It is an arithmetic number, because the mean of its divisors is an integer number (10213629).

Almost surely, 2^20427257 is an apocalyptic number.

It is an amenable number.

20427257 is a deficient number, since it is larger than the sum of its proper divisors (1).

20427257 is an equidigital number, since it uses as much as digits as its factorization.

20427257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7840, while the sum is 29.

The square root of 20427257 is about 4519.6523096362. The cubic root of 20427257 is about 273.3610816895.

Adding to 20427257 its reverse (75272402), we get a palindrome (95699659).

The spelling of 20427257 in words is "twenty million, four hundred twenty-seven thousand, two hundred fifty-seven".