1378776666901 has 2 divisors, whose sum is σ = 1378776666902. Its totient is φ = 1378776666900.

The previous prime is 1378776666887. The next prime is 1378776666937. The reversal of 1378776666901 is 1096666778731.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 763830552676 + 614946114225 = 873974^2 + 784185^2 .

It is a cyclic number.

It is not a de Polignac number, because 1378776666901 - 2¹³ = 1378776658709 is a prime.

It is a super-2 number, since 2×1378776666901² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1378776606901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 689388333450 + 689388333451.

It is an arithmetic number, because the mean of its divisors is an integer number (689388333451).

Almost surely, 2^{1378776666901} is an apocalyptic number.

It is an amenable number.

1378776666901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1378776666901 is an equidigital number, since it uses as much as digits as its factorization.

1378776666901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96018048, while the sum is 67.

The spelling of 1378776666901 in words is "one trillion, three hundred seventy-eight billion, seven hundred seventy-six million, six hundred sixty-six thousand, nine hundred one".