1398695989 has 2 divisors, whose sum is σ = 1398695990. Its totient is φ = 1398695988.

The previous prime is 1398695981. The next prime is 1398695999. The reversal of 1398695989 is 9895968931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 958955089 + 439740900 = 30967^2 + 20970^2 .

It is a cyclic number.

It is not a de Polignac number, because 1398695989 - 2³ = 1398695981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1398695981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 699347994 + 699347995.

It is an arithmetic number, because the mean of its divisors is an integer number (699347995).

Almost surely, 2^1398695989 is an apocalyptic number.

It is an amenable number.

1398695989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1398695989 is an equidigital number, since it uses as much as digits as its factorization.

1398695989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37791360, while the sum is 67.

The square root of 1398695989 is about 37399.1442281772. The cubic root of 1398695989 is about 1118.3415049762.

The spelling of 1398695989 in words is "one billion, three hundred ninety-eight million, six hundred ninety-five thousand, nine hundred eighty-nine".