819866969 has 2 divisors, whose sum is σ = 819866970. Its totient is φ = 819866968.

The previous prime is 819866941. The next prime is 819867001. The reversal of 819866969 is 969668918.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 767954944 + 51912025 = 27712^2 + 7205^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-819866969 is a prime.

It is a super-2 number, since 2×819866969² = 1344363693714493922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (819866909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409933484 + 409933485.

It is an arithmetic number, because the mean of its divisors is an integer number (409933485).

Almost surely, 2^819866969 is an apocalyptic number.

It is an amenable number.

819866969 is a deficient number, since it is larger than the sum of its proper divisors (1).

819866969 is an equidigital number, since it uses as much as digits as its factorization.

819866969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10077696, while the sum is 62.

The square root of 819866969 is about 28633.3192103186. The cubic root of 819866969 is about 935.9395434355.

The spelling of 819866969 in words is "eight hundred nineteen million, eight hundred sixty-six thousand, nine hundred sixty-nine".