20540745 has 12 divisors (see below), whose sum is σ = 35604036. Its totient is φ = 10955040.

The previous prime is 20540731. The next prime is 20540747. The reversal of 20540745 is 54704502.

It can be written as a sum of positive squares in 2 ways, for example, as 3697929 + 16842816 = 1923^2 + 4104^2 .

It is not a de Polignac number, because 20540745 - 2²³ = 12152137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20540747) 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 in 11 ways as a sum of consecutive naturals, for example, 228186 + ... + 228275.

It is an arithmetic number, because the mean of its divisors is an integer number (2967003).

Almost surely, 2^20540745 is an apocalyptic number.

It is an amenable number.

20540745 is a deficient number, since it is larger than the sum of its proper divisors (15063291).

20540745 is a wasteful number, since it uses less digits than its factorization.

20540745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456472 (or 456469 counting only the distinct ones).

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

The square root of 20540745 is about 4532.1898680439. The cubic root of 20540745 is about 273.8663857398.

The spelling of 20540745 in words is "twenty million, five hundred forty thousand, seven hundred forty-five".