418663681 has 2 divisors, whose sum is σ = 418663682. Its totient is φ = 418663680.

The previous prime is 418663667. The next prime is 418663697. The reversal of 418663681 is 186366814.

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., 354983281 + 63680400 = 18841^2 + 7980^2 .

It is a cyclic number.

It is not a de Polignac number, because 418663681 - 2²¹ = 416566529 is a prime.

It is a super-2 number, since 2×418663681² = 350558555576939522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (418663631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 209331840 + 209331841.

It is an arithmetic number, because the mean of its divisors is an integer number (209331841).

Almost surely, 2^418663681 is an apocalyptic number.

It is an amenable number.

418663681 is a deficient number, since it is larger than the sum of its proper divisors (1).

418663681 is an equidigital number, since it uses as much as digits as its factorization.

418663681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 165888, while the sum is 43.

The square root of 418663681 is about 20461.2727121262. The cubic root of 418663681 is about 748.0921470596.

The spelling of 418663681 in words is "four hundred eighteen million, six hundred sixty-three thousand, six hundred eighty-one".