1978243102573 has 4 divisors (see below), whose sum is σ = 1978669728540. Its totient is φ = 1977816476608.

The previous prime is 1978243102553. The next prime is 1978243102609. The reversal of 1978243102573 is 3752013428791.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 179366649289 + 1798876453284 = 423517^2 + 1341222^2 .

It is a cyclic number.

It is not a de Polignac number, because 1978243102573 - 2⁵ = 1978243102541 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1978243102573.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978243102543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213306028 + ... + 213315301.

It is an arithmetic number, because the mean of its divisors is an integer number (494667432135).

Almost surely, 2^{1978243102573} is an apocalyptic number.

It is an amenable number.

1978243102573 is a deficient number, since it is larger than the sum of its proper divisors (426625967).

1978243102573 is an equidigital number, since it uses as much as digits as its factorization.

1978243102573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426625966.

The product of its (nonzero) digits is 2540160, while the sum is 52.

The spelling of 1978243102573 in words is "one trillion, nine hundred seventy-eight billion, two hundred forty-three million, one hundred two thousand, five hundred seventy-three".