1320560721 has 12 divisors (see below), whose sum is σ = 1908345348. Its totient is φ = 879972864.

The previous prime is 1320560711. The next prime is 1320560741. The reversal of 1320560721 is 1270650231.

It is a happy number.

1320560721 is a `hidden beast` number, since 1 + 32 + 0 + 5 + 607 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 494573121 + 825987600 = 22239^2 + 28740^2 .

It is not a de Polignac number, because 1320560721 - 2⁹ = 1320560209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1320560701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11820 + ... + 52733.

It is an arithmetic number, because the mean of its divisors is an integer number (159028779).

Almost surely, 2^1320560721 is an apocalyptic number.

It is an amenable number.

1320560721 is a deficient number, since it is larger than the sum of its proper divisors (587784627).

1320560721 is a wasteful number, since it uses less digits than its factorization.

1320560721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66832 (or 66829 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 1320560721 is about 36339.5200986474. The cubic root of 1320560721 is about 1097.1166140646.

The spelling of 1320560721 in words is "one billion, three hundred twenty million, five hundred sixty thousand, seven hundred twenty-one".