1391639441 has 2 divisors, whose sum is σ = 1391639442. Its totient is φ = 1391639440.

The previous prime is 1391639423. The next prime is 1391639461. The reversal of 1391639441 is 1449361931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1203812416 + 187827025 = 34696^2 + 13705^2 .

It is a cyclic number.

It is not a de Polignac number, because 1391639441 - 2¹⁸ = 1391377297 is a prime.

It is not a weakly prime, because it can be changed into another prime (1391639461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695819720 + 695819721.

It is an arithmetic number, because the mean of its divisors is an integer number (695819721).

Almost surely, 2^1391639441 is an apocalyptic number.

It is an amenable number.

1391639441 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391639441 is an equidigital number, since it uses as much as digits as its factorization.

1391639441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 41.

The square root of 1391639441 is about 37304.6839016229. The cubic root of 1391639441 is about 1116.4576218867.

The spelling of 1391639441 in words is "one billion, three hundred ninety-one million, six hundred thirty-nine thousand, four hundred forty-one".