20475817 has 2 divisors, whose sum is σ = 20475818. Its totient is φ = 20475816.

The previous prime is 20475799. The next prime is 20475839. The reversal of 20475817 is 71857402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14600041 + 5875776 = 3821^2 + 2424^2 .

It is a cyclic number.

It is not a de Polignac number, because 20475817 - 2¹¹ = 20473769 is a prime.

It is equal to p_1298824 and since 20475817 and 1298824 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20475857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10237908 + 10237909.

It is an arithmetic number, because the mean of its divisors is an integer number (10237909).

Almost surely, 2^20475817 is an apocalyptic number.

It is an amenable number.

20475817 is a deficient number, since it is larger than the sum of its proper divisors (1).

20475817 is an equidigital number, since it uses as much as digits as its factorization.

20475817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 20475817 is about 4525.0212154199. The cubic root of 20475817 is about 273.5775230401.

The spelling of 20475817 in words is "twenty million, four hundred seventy-five thousand, eight hundred seventeen".