20444257 has 2 divisors, whose sum is σ = 20444258. Its totient is φ = 20444256.

The previous prime is 20444233. The next prime is 20444261. The reversal of 20444257 is 75244402.

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., 19927296 + 516961 = 4464^2 + 719^2 .

It is a cyclic number.

It is not a de Polignac number, because 20444257 - 2¹⁹ = 19919969 is a prime.

It is not a weakly prime, because it can be changed into another prime (20444227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10222128 + 10222129.

It is an arithmetic number, because the mean of its divisors is an integer number (10222129).

Almost surely, 2^20444257 is an apocalyptic number.

It is an amenable number.

20444257 is a deficient number, since it is larger than the sum of its proper divisors (1).

20444257 is an equidigital number, since it uses as much as digits as its factorization.

20444257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8960, while the sum is 28.

The square root of 20444257 is about 4521.5325941543. The cubic root of 20444257 is about 273.4368929750.

Adding to 20444257 its reverse (75244402), we get a palindrome (95688659).

The spelling of 20444257 in words is "twenty million, four hundred forty-four thousand, two hundred fifty-seven".