1320208591 has 4 divisors (see below), whose sum is σ = 1421763112. Its totient is φ = 1218654072.

The previous prime is 1320208567. The next prime is 1320208601. The reversal of 1320208591 is 1958020231.

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

It is a cyclic number.

It is not a de Polignac number, because 1320208591 - 2¹¹ = 1320206543 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 (1320208511) 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, 50777241 + ... + 50777266.

It is an arithmetic number, because the mean of its divisors is an integer number (355440778).

Almost surely, 2^1320208591 is an apocalyptic number.

1320208591 is a deficient number, since it is larger than the sum of its proper divisors (101554521).

1320208591 is a wasteful number, since it uses less digits than its factorization.

1320208591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101554520.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1320208591 is about 36334.6747749309. The cubic root of 1320208591 is about 1097.0190893262.

The spelling of 1320208591 in words is "one billion, three hundred twenty million, two hundred eight thousand, five hundred ninety-one".