813779969 has 2 divisors, whose sum is σ = 813779970. Its totient is φ = 813779968.

The previous prime is 813779929. The next prime is 813780001. The reversal of 813779969 is 969977318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 806560000 + 7219969 = 28400^2 + 2687^2 .

It is a cyclic number.

It is not a de Polignac number, because 813779969 - 2⁸ = 813779713 is a prime.

It is a super-2 number, since 2×813779969² = 1324475675891281922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (813779929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406889984 + 406889985.

It is an arithmetic number, because the mean of its divisors is an integer number (406889985).

Almost surely, 2^813779969 is an apocalyptic number.

It is an amenable number.

813779969 is a deficient number, since it is larger than the sum of its proper divisors (1).

813779969 is an equidigital number, since it uses as much as digits as its factorization.

813779969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5143824, while the sum is 59.

The square root of 813779969 is about 28526.8289334794. The cubic root of 813779969 is about 933.6175319764.

The spelling of 813779969 in words is "eight hundred thirteen million, seven hundred seventy-nine thousand, nine hundred sixty-nine".