2780888891945 has 4 divisors (see below), whose sum is σ = 3337066670340. Its totient is φ = 2224711113552.

The previous prime is 2780888891923. The next prime is 2780888892013. The reversal of 2780888891945 is 5491988880872.

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 1471026953881 + 1309861938064 = 1212859^2 + 1144492^2 .

It is a cyclic number.

It is not a de Polignac number, because 2780888891945 - 2¹² = 2780888887849 is a prime.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 278088889190 + ... + 278088889199.

It is an arithmetic number, because the mean of its divisors is an integer number (834266667585).

Almost surely, 2^{2780888891945} is an apocalyptic number.

It is an amenable number.

2780888891945 is a deficient number, since it is larger than the sum of its proper divisors (556177778395).

2780888891945 is an equidigital number, since it uses as much as digits as its factorization.

2780888891945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556177778394.

The product of its (nonzero) digits is 743178240, while the sum is 77.

The spelling of 2780888891945 in words is "two trillion, seven hundred eighty billion, eight hundred eighty-eight million, eight hundred ninety-one thousand, nine hundred forty-five".