1320399264 has 48 divisors (see below), whose sum is σ = 3477200832. Its totient is φ = 438716928.

The previous prime is 1320399263. The next prime is 1320399307. The reversal of 1320399264 is 4629930231.

It is a tau number, because it is divible by the number of its divisors (48).

It is not an unprimeable number, because it can be changed into a prime (1320399263) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8077 + ... + 52019.

It is an arithmetic number, because the mean of its divisors is an integer number (72441684).

Almost surely, 2^1320399264 is an apocalyptic number.

It is an amenable number.

1320399264 is an abundant number, since it is smaller than the sum of its proper divisors (2156801568).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1320399264 is a wasteful number, since it uses less digits than its factorization.

1320399264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44269 (or 44261 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 39.

The square root of 1320399264 is about 36337.2985236933. The cubic root of 1320399264 is about 1097.0718996303.

The spelling of 1320399264 in words is "one billion, three hundred twenty million, three hundred ninety-nine thousand, two hundred sixty-four".