1320645671 has 4 divisors (see below), whose sum is σ = 1378065072. Its totient is φ = 1263226272.

The previous prime is 1320645649. The next prime is 1320645719. The reversal of 1320645671 is 1765460231.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320645671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320645871) 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, 28709666 + ... + 28709711.

It is an arithmetic number, because the mean of its divisors is an integer number (344516268).

Almost surely, 2^1320645671 is an apocalyptic number.

1320645671 is a deficient number, since it is larger than the sum of its proper divisors (57419401).

1320645671 is an equidigital number, since it uses as much as digits as its factorization.

1320645671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57419400.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 1320645671 is about 36340.6889175205. The cubic root of 1320645671 is about 1097.1401389346.

The spelling of 1320645671 in words is "one billion, three hundred twenty million, six hundred forty-five thousand, six hundred seventy-one".