1863988961 has 2 divisors, whose sum is σ = 1863988962. Its totient is φ = 1863988960.

The previous prime is 1863988921. The next prime is 1863988967. The reversal of 1863988961 is 1698893681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1818169600 + 45819361 = 42640^2 + 6769^2 .

It is an emirp because it is prime and its reverse (1698893681) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1863988961 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1863988961.

It is not a weakly prime, because it can be changed into another prime (1863988967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 931994480 + 931994481.

It is an arithmetic number, because the mean of its divisors is an integer number (931994481).

Almost surely, 2^1863988961 is an apocalyptic number.

It is an amenable number.

1863988961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1863988961 is an equidigital number, since it uses as much as digits as its factorization.

1863988961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4478976, while the sum is 59.

The square root of 1863988961 is about 43173.9384467065. The cubic root of 1863988961 is about 1230.6874692598.

The spelling of 1863988961 in words is "one billion, eight hundred sixty-three million, nine hundred eighty-eight thousand, nine hundred sixty-one".