819685949 has 2 divisors, whose sum is σ = 819685950. Its totient is φ = 819685948.

The previous prime is 819685939. The next prime is 819685967. The reversal of 819685949 is 949586918.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 556110724 + 263575225 = 23582^2 + 16235^2 .

It is a cyclic number.

It is not a de Polignac number, because 819685949 - 2⁸ = 819685693 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (819685939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409842974 + 409842975.

It is an arithmetic number, because the mean of its divisors is an integer number (409842975).

Almost surely, 2^819685949 is an apocalyptic number.

It is an amenable number.

819685949 is a deficient number, since it is larger than the sum of its proper divisors (1).

819685949 is an equidigital number, since it uses as much as digits as its factorization.

819685949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5598720, while the sum is 59.

The square root of 819685949 is about 28630.1580330951. The cubic root of 819685949 is about 935.8706557365.

The spelling of 819685949 in words is "eight hundred nineteen million, six hundred eighty-five thousand, nine hundred forty-nine".