1977769813 has 2 divisors, whose sum is σ = 1977769814. Its totient is φ = 1977769812.

The previous prime is 1977769789. The next prime is 1977769841. The reversal of 1977769813 is 3189677791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1565151844 + 412617969 = 39562^2 + 20313^2 .

It is a cyclic number.

It is not a de Polignac number, because 1977769813 - 2⁹ = 1977769301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1977769853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 988884906 + 988884907.

It is an arithmetic number, because the mean of its divisors is an integer number (988884907).

Almost surely, 2^1977769813 is an apocalyptic number.

It is an amenable number.

1977769813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1977769813 is an equidigital number, since it uses as much as digits as its factorization.

1977769813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4000752, while the sum is 58.

The square root of 1977769813 is about 44472.1239991975. The cubic root of 1977769813 is about 1255.2356002817.

The spelling of 1977769813 in words is "one billion, nine hundred seventy-seven million, seven hundred sixty-nine thousand, eight hundred thirteen".