1378836491 has 2 divisors, whose sum is σ = 1378836492. Its totient is φ = 1378836490.

The previous prime is 1378836457. The next prime is 1378836541. The reversal of 1378836491 is 1946388731.

It is an a-pointer prime, because the next prime (1378836541) can be obtained adding 1378836491 to its sum of digits (50).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1378836491 - 2¹⁰ = 1378835467 is a prime.

It is not a weakly prime, because it can be changed into another prime (1378836451) 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, 689418245 + 689418246.

It is an arithmetic number, because the mean of its divisors is an integer number (689418246).

Almost surely, 2^1378836491 is an apocalyptic number.

1378836491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1378836491 is an equidigital number, since it uses as much as digits as its factorization.

1378836491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 50.

The square root of 1378836491 is about 37132.6876350204. The cubic root of 1378836491 is about 1113.0233006012.

The spelling of 1378836491 in words is "one billion, three hundred seventy-eight million, eight hundred thirty-six thousand, four hundred ninety-one".