1978876129 has 2 divisors, whose sum is σ = 1978876130. Its totient is φ = 1978876128.

The previous prime is 1978876117. The next prime is 1978876147. The reversal of 1978876129 is 9216788791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1934680225 + 44195904 = 43985^2 + 6648^2 .

It is a cyclic number.

It is not a de Polignac number, because 1978876129 - 2⁹ = 1978875617 is a prime.

It is not a weakly prime, because it can be changed into another prime (1978874129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989438064 + 989438065.

It is an arithmetic number, because the mean of its divisors is an integer number (989438065).

Almost surely, 2^1978876129 is an apocalyptic number.

It is an amenable number.

1978876129 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978876129 is an equidigital number, since it uses as much as digits as its factorization.

1978876129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 58.

The square root of 1978876129 is about 44484.5605688086. The cubic root of 1978876129 is about 1255.4696060066.

The spelling of 1978876129 in words is "one billion, nine hundred seventy-eight million, eight hundred seventy-six thousand, one hundred twenty-nine".