1778561122979 has 2 divisors, whose sum is σ = 1778561122980. Its totient is φ = 1778561122978.

The previous prime is 1778561122973. The next prime is 1778561123041. The reversal of 1778561122979 is 9792211658771.

It is a weak prime.

It is an emirp because it is prime and its reverse (9792211658771) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1778561122979 - 2²⁴ = 1778544345763 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1778561122973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 889280561489 + 889280561490.

It is an arithmetic number, because the mean of its divisors is an integer number (889280561490).

Almost surely, 2^{1778561122979} is an apocalyptic number.

1778561122979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1778561122979 is an equidigital number, since it uses as much as digits as its factorization.

1778561122979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26671680, while the sum is 65.

The spelling of 1778561122979 in words is "one trillion, seven hundred seventy-eight billion, five hundred sixty-one million, one hundred twenty-two thousand, nine hundred seventy-nine".