1345997809 has 4 divisors (see below), whose sum is σ = 1449536116. Its totient is φ = 1242459504.

The previous prime is 1345997801. The next prime is 1345997837. The reversal of 1345997809 is 9087995431.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 355511025 + 990486784 = 18855^2 + 31472^2 .

It is not a de Polignac number, because 1345997809 - 2³ = 1345997801 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1345997809.

It is not an unprimeable number, because it can be changed into a prime (1345997801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51769134 + ... + 51769159.

It is an arithmetic number, because the mean of its divisors is an integer number (362384029).

Almost surely, 2^1345997809 is an apocalyptic number.

It is an amenable number.

1345997809 is a deficient number, since it is larger than the sum of its proper divisors (103538307).

1345997809 is a wasteful number, since it uses less digits than its factorization.

1345997809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103538306.

The product of its (nonzero) digits is 2449440, while the sum is 55.

The square root of 1345997809 is about 36687.8427956728. The cubic root of 1345997809 is about 1104.1162057477.

The spelling of 1345997809 in words is "one billion, three hundred forty-five million, nine hundred ninety-seven thousand, eight hundred nine".