20670817 has 2 divisors, whose sum is σ = 20670818. Its totient is φ = 20670816.

The previous prime is 20670763. The next prime is 20670851. The reversal of 20670817 is 71807602.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11128896 + 9541921 = 3336^2 + 3089^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20670817 is a prime.

It is not a weakly prime, because it can be changed into another prime (20670877) 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 as a sum of consecutive naturals, namely, 10335408 + 10335409.

It is an arithmetic number, because the mean of its divisors is an integer number (10335409).

Almost surely, 2^20670817 is an apocalyptic number.

It is an amenable number.

20670817 is a deficient number, since it is larger than the sum of its proper divisors (1).

20670817 is an equidigital number, since it uses as much as digits as its factorization.

20670817 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 20670817 is about 4546.5170185539. The cubic root of 20670817 is about 274.4432460307.

The spelling of 20670817 in words is "twenty million, six hundred seventy thousand, eight hundred seventeen".