20457905 has 16 divisors (see below), whose sum is σ = 27352080. Its totient is φ = 14585088.

The previous prime is 20457901. The next prime is 20457911. The reversal of 20457905 is 50975402.

It can be written as a sum of positive squares in 8 ways, for example, as 1106704 + 19351201 = 1052^2 + 4399^2 .

It is a cyclic number.

It is not a de Polignac number, because 20457905 - 2² = 20457901 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20457901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3542 + ... + 7311.

It is an arithmetic number, because the mean of its divisors is an integer number (1709505).

Almost surely, 2^20457905 is an apocalyptic number.

It is an amenable number.

20457905 is a deficient number, since it is larger than the sum of its proper divisors (6894175).

20457905 is a wasteful number, since it uses less digits than its factorization.

20457905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10900.

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 20457905 is about 4523.0415651418. The cubic root of 20457905 is about 273.4977256511.

The spelling of 20457905 in words is "twenty million, four hundred fifty-seven thousand, nine hundred five".