1398535609 has 3 divisors (see below), whose sum is σ = 1398573007. Its totient is φ = 1398498212.

The previous prime is 1398535597. The next prime is 1398535669. The reversal of 1398535609 is 9065358931.

It is a happy number.

The square root of 1398535609 is 37397.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 389075625 + 1009459984 = 19725^2 + 31772^2 .

It is not a de Polignac number, because 1398535609 - 2⁵ = 1398535577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1398535669) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 18699 + ... + 56095.

Almost surely, 2^1398535609 is an apocalyptic number.

1398535609 is the 37397-th square number.

1398535609 is the 18699-th centered octagonal number.

It is an amenable number.

1398535609 is a deficient number, since it is larger than the sum of its proper divisors (37398).

1398535609 is an frugal number, since it uses more digits than its factorization.

1398535609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74794 (or 37397 counting only the distinct ones).

The product of its (nonzero) digits is 874800, while the sum is 49.

The cubic root of 1398535609 is about 1118.2987588594.

Multiplying 1398535609 by its sum of digits (49), we get a square (68528244841 = 261779²).

It can be divided in two parts, 13985 and 35609, that added together give a palindrome (49594).

The spelling of 1398535609 in words is "one billion, three hundred ninety-eight million, five hundred thirty-five thousand, six hundred nine".