20493257 has 2 divisors, whose sum is σ = 20493258. Its totient is φ = 20493256.

The previous prime is 20493197. The next prime is 20493271. The reversal of 20493257 is 75239402.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20259001 + 234256 = 4501^2 + 484^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20493257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20490257) 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, 10246628 + 10246629.

It is an arithmetic number, because the mean of its divisors is an integer number (10246629).

Almost surely, 2^20493257 is an apocalyptic number.

It is an amenable number.

20493257 is a deficient number, since it is larger than the sum of its proper divisors (1).

20493257 is an equidigital number, since it uses as much as digits as its factorization.

20493257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 32.

The square root of 20493257 is about 4526.9478680453. The cubic root of 20493257 is about 273.6551729827.

The spelling of 20493257 in words is "twenty million, four hundred ninety-three thousand, two hundred fifty-seven".