1989956677 has 2 divisors, whose sum is σ = 1989956678. Its totient is φ = 1989956676.

The previous prime is 1989956627. The next prime is 1989956707. The reversal of 1989956677 is 7766599891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1975713601 + 14243076 = 44449^2 + 3774^2 .

It is an emirp because it is prime and its reverse (7766599891) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1989956677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1989956627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994978338 + 994978339.

It is an arithmetic number, because the mean of its divisors is an integer number (994978339).

Almost surely, 2^1989956677 is an apocalyptic number.

It is an amenable number.

1989956677 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989956677 is an equidigital number, since it uses as much as digits as its factorization.

1989956677 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51438240, while the sum is 67.

The square root of 1989956677 is about 44608.9304624085. The cubic root of 1989956677 is about 1257.8085441663.

The spelling of 1989956677 in words is "one billion, nine hundred eighty-nine million, nine hundred fifty-six thousand, six hundred seventy-seven".