1979306809 has 2 divisors, whose sum is σ = 1979306810. Its totient is φ = 1979306808.

The previous prime is 1979306803. The next prime is 1979306827. The reversal of 1979306809 is 9086039791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1953905209 + 25401600 = 44203^2 + 5040^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1979306809 is a prime.

It is not a weakly prime, because it can be changed into another prime (1979306803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989653404 + 989653405.

It is an arithmetic number, because the mean of its divisors is an integer number (989653405).

Almost surely, 2^1979306809 is an apocalyptic number.

It is an amenable number.

1979306809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1979306809 is an equidigital number, since it uses as much as digits as its factorization.

1979306809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 734832, while the sum is 52.

The square root of 1979306809 is about 44489.4010861014. The cubic root of 1979306809 is about 1255.5606789850.

The spelling of 1979306809 in words is "one billion, nine hundred seventy-nine million, three hundred six thousand, eight hundred nine".