1398378709 has 24 divisors (see below), whose sum is σ = 1755855360. Its totient is φ = 1103858784.

The previous prime is 1398378643. The next prime is 1398378713. The reversal of 1398378709 is 9078738931.

It is not a de Polignac number, because 1398378709 - 2¹⁵ = 1398345941 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1398378709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1398378719) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 302832 + ... + 307414.

It is an arithmetic number, because the mean of its divisors is an integer number (73160640).

Almost surely, 2^1398378709 is an apocalyptic number.

It is an amenable number.

1398378709 is a deficient number, since it is larger than the sum of its proper divisors (357476651).

1398378709 is a wasteful number, since it uses less digits than its factorization.

1398378709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5089 (or 5082 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 55.

The square root of 1398378709 is about 37394.9021793078. The cubic root of 1398378709 is about 1118.2569371053.

The spelling of 1398378709 in words is "one billion, three hundred ninety-eight million, three hundred seventy-eight thousand, seven hundred nine".