1963439981 has 2 divisors, whose sum is σ = 1963439982. Its totient is φ = 1963439980.

The previous prime is 1963439977. The next prime is 1963440043. The reversal of 1963439981 is 1899343691.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1605284356 + 358155625 = 40066^2 + 18925^2 .

It is a cyclic number.

It is not a de Polignac number, because 1963439981 - 2² = 1963439977 is a prime.

It is a super-2 number, since 2×1963439981² = 7710193117978560722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1963439381) 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, 981719990 + 981719991.

It is an arithmetic number, because the mean of its divisors is an integer number (981719991).

Almost surely, 2^1963439981 is an apocalyptic number.

It is an amenable number.

1963439981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1963439981 is an equidigital number, since it uses as much as digits as its factorization.

1963439981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1259712, while the sum is 53.

The square root of 1963439981 is about 44310.7208359331. The cubic root of 1963439981 is about 1252.1966667429.

The spelling of 1963439981 in words is "one billion, nine hundred sixty-three million, four hundred thirty-nine thousand, nine hundred eighty-one".