1978975618813 has 2 divisors, whose sum is σ = 1978975618814. Its totient is φ = 1978975618812.

The previous prime is 1978975618793. The next prime is 1978975618847. The reversal of 1978975618813 is 3188165798791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1528356095289 + 450619523524 = 1236267^2 + 671282^2 .

It is a cyclic number.

It is not a de Polignac number, because 1978975618813 - 2³³ = 1970385684221 is a prime.

It is a super-3 number, since 3×1978975618813³ (a number of 38 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1978975618513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989487809406 + 989487809407.

It is an arithmetic number, because the mean of its divisors is an integer number (989487809407).

Almost surely, 2^{1978975618813} is an apocalyptic number.

It is an amenable number.

1978975618813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978975618813 is an equidigital number, since it uses as much as digits as its factorization.

1978975618813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 182891520, while the sum is 73.

The spelling of 1978975618813 in words is "one trillion, nine hundred seventy-eight billion, nine hundred seventy-five million, six hundred eighteen thousand, eight hundred thirteen".