1331420809 has 4 divisors (see below), whose sum is σ = 1331494416. Its totient is φ = 1331347204.

The previous prime is 1331420789. The next prime is 1331420819. The reversal of 1331420809 is 9080241331.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1331420809 - 2⁷ = 1331420681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1331420819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11202 + ... + 52804.

It is an arithmetic number, because the mean of its divisors is an integer number (332873604).

Almost surely, 2^1331420809 is an apocalyptic number.

It is an amenable number.

1331420809 is a deficient number, since it is larger than the sum of its proper divisors (73607).

1331420809 is an equidigital number, since it uses as much as digits as its factorization.

1331420809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73606.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 1331420809 is about 36488.6394512045. The cubic root of 1331420809 is about 1100.1159131295.

The spelling of 1331420809 in words is "one billion, three hundred thirty-one million, four hundred twenty thousand, eight hundred nine".