20445057 has 6 divisors (see below), whose sum is σ = 29531762. Its totient is φ = 13630032.

The previous prime is 20445041. The next prime is 20445071. The reversal of 20445057 is 75054402.

20445057 is a `hidden beast` number, since 204 + 450 + 5 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13024881 + 7420176 = 3609^2 + 2724^2 .

It is not a de Polignac number, because 20445057 - 2⁴ = 20445041 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20445057.

It is not an unprimeable number, because it can be changed into a prime (20445017) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1135828 + ... + 1135845.

Almost surely, 2^20445057 is an apocalyptic number.

It is an amenable number.

20445057 is a deficient number, since it is larger than the sum of its proper divisors (9086705).

20445057 is a wasteful number, since it uses less digits than its factorization.

20445057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2271679 (or 2271676 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 27.

The square root of 20445057 is about 4521.6210588682. The cubic root of 20445057 is about 273.4404595293.

Adding to 20445057 its reverse (75054402), we get a palindrome (95499459).

The spelling of 20445057 in words is "twenty million, four hundred forty-five thousand, fifty-seven".