2778505505497 has 2 divisors, whose sum is σ = 2778505505498. Its totient is φ = 2778505505496.

The previous prime is 2778505505437. The next prime is 2778505505507. The reversal of 2778505505497 is 7945055058772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2445958369936 + 332547135561 = 1563956^2 + 576669^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2778505505497 is a prime.

It is not a weakly prime, because it can be changed into another prime (2778505505407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1389252752748 + 1389252752749.

It is an arithmetic number, because the mean of its divisors is an integer number (1389252752749).

Almost surely, 2^{2778505505497} is an apocalyptic number.

It is an amenable number.

2778505505497 is a deficient number, since it is larger than the sum of its proper divisors (1).

2778505505497 is an equidigital number, since it uses as much as digits as its factorization.

2778505505497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 123480000, while the sum is 64.

The spelling of 2778505505497 in words is "two trillion, seven hundred seventy-eight billion, five hundred five million, five hundred five thousand, four hundred ninety-seven".