1381378657 has 2 divisors, whose sum is σ = 1381378658. Its totient is φ = 1381378656.

The previous prime is 1381378651. The next prime is 1381378699. The reversal of 1381378657 is 7568731831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1336341136 + 45037521 = 36556^2 + 6711^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1381378657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1381378657.

It is not a weakly prime, because it can be changed into another prime (1381378651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690689328 + 690689329.

It is an arithmetic number, because the mean of its divisors is an integer number (690689329).

Almost surely, 2^1381378657 is an apocalyptic number.

It is an amenable number.

1381378657 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381378657 is an equidigital number, since it uses as much as digits as its factorization.

1381378657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720, while the sum is 49.

The square root of 1381378657 is about 37166.9027092654. The cubic root of 1381378657 is about 1113.7069090579.

The spelling of 1381378657 in words is "one billion, three hundred eighty-one million, three hundred seventy-eight thousand, six hundred fifty-seven".