819678961 has 2 divisors, whose sum is σ = 819678962. Its totient is φ = 819678960.

The previous prime is 819678907. The next prime is 819678989. The reversal of 819678961 is 169876918.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 788542561 + 31136400 = 28081^2 + 5580^2 .

It is a cyclic number.

It is not a de Polignac number, because 819678961 - 2¹³ = 819670769 is a prime.

It is not a weakly prime, because it can be changed into another prime (819678901) 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, 409839480 + 409839481.

It is an arithmetic number, because the mean of its divisors is an integer number (409839481).

Almost surely, 2^819678961 is an apocalyptic number.

It is an amenable number.

819678961 is a deficient number, since it is larger than the sum of its proper divisors (1).

819678961 is an equidigital number, since it uses as much as digits as its factorization.

819678961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1306368, while the sum is 55.

The square root of 819678961 is about 28630.0359936903. The cubic root of 819678961 is about 935.8679962291.

The spelling of 819678961 in words is "eight hundred nineteen million, six hundred seventy-eight thousand, nine hundred sixty-one".