1398378643 has 2 divisors, whose sum is σ = 1398378644. Its totient is φ = 1398378642.

The previous prime is 1398378617. The next prime is 1398378713. The reversal of 1398378643 is 3468738931.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1398378643 is a prime.

It is not a weakly prime, because it can be changed into another prime (1398378143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 699189321 + 699189322.

It is an arithmetic number, because the mean of its divisors is an integer number (699189322).

Almost surely, 2^1398378643 is an apocalyptic number.

1398378643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1398378643 is an equidigital number, since it uses as much as digits as its factorization.

1398378643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2612736, while the sum is 52.

The square root of 1398378643 is about 37394.9012968346. The cubic root of 1398378643 is about 1118.2569195123.

The spelling of 1398378643 in words is "one billion, three hundred ninety-eight million, three hundred seventy-eight thousand, six hundred forty-three".