20471745 has 32 divisors (see below), whose sum is σ = 37635840. Its totient is φ = 9308160.

The previous prime is 20471719. The next prime is 20471747. The reversal of 20471745 is 54717402.

It is not a de Polignac number, because 20471745 - 2⁵ = 20471713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20471747) 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 31 ways as a sum of consecutive naturals, for example, 24901 + ... + 25709.

It is an arithmetic number, because the mean of its divisors is an integer number (1176120).

Almost surely, 2^20471745 is an apocalyptic number.

It is an amenable number.

20471745 is a deficient number, since it is larger than the sum of its proper divisors (17164095).

20471745 is a wasteful number, since it uses less digits than its factorization.

20471745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1065.

The product of its (nonzero) digits is 7840, while the sum is 30.

The square root of 20471745 is about 4524.5712504059. The cubic root of 20471745 is about 273.5593864983.

The spelling of 20471745 in words is "twenty million, four hundred seventy-one thousand, seven hundred forty-five".