1389565809 has 12 divisors (see below), whose sum is σ = 2056106052. Its totient is φ = 903782400.

The previous prime is 1389565789. The next prime is 1389565823. The reversal of 1389565809 is 9085659831.

It is a happy number.

1389565809 is a `hidden beast` number, since 1 + 3 + 8 + 9 + 56 + 580 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 503015184 + 886550625 = 22428^2 + 29775^2 .

It is not a de Polignac number, because 1389565809 - 2⁸ = 1389565553 is a prime.

It is a super-4 number, since 4×1389565809⁴ (a number of 38 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (1389565829) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1882512 + ... + 1883249.

It is an arithmetic number, because the mean of its divisors is an integer number (171342171).

Almost surely, 2^1389565809 is an apocalyptic number.

It is an amenable number.

1389565809 is a deficient number, since it is larger than the sum of its proper divisors (666540243).

1389565809 is a wasteful number, since it uses less digits than its factorization.

1389565809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3765808 (or 3765805 counting only the distinct ones).

The product of its (nonzero) digits is 2332800, while the sum is 54.

The square root of 1389565809 is about 37276.8803549868. The cubic root of 1389565809 is about 1115.9028150812.

The spelling of 1389565809 in words is "one billion, three hundred eighty-nine million, five hundred sixty-five thousand, eight hundred nine".