20218669 has 2 divisors, whose sum is σ = 20218670. Its totient is φ = 20218668.

The previous prime is 20218637. The next prime is 20218673. The reversal of 20218669 is 96681202.

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., 10989225 + 9229444 = 3315^2 + 3038^2 .

It is a cyclic number.

It is not a de Polignac number, because 20218669 - 2⁵ = 20218637 is a prime.

It is a super-2 number, since 2×20218669² = 817589152263122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20218609) 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 as a sum of consecutive naturals, namely, 10109334 + 10109335.

It is an arithmetic number, because the mean of its divisors is an integer number (10109335).

Almost surely, 2^20218669 is an apocalyptic number.

It is an amenable number.

20218669 is a deficient number, since it is larger than the sum of its proper divisors (1).

20218669 is an equidigital number, since it uses as much as digits as its factorization.

20218669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 20218669 is about 4496.5174301897. The cubic root of 20218669 is about 272.4274430172.

The spelling of 20218669 in words is "twenty million, two hundred eighteen thousand, six hundred sixty-nine".