1320580661 has 2 divisors, whose sum is σ = 1320580662. Its totient is φ = 1320580660.

The previous prime is 1320580637. The next prime is 1320580711. The reversal of 1320580661 is 1660850231.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1207562500 + 113018161 = 34750^2 + 10631^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320580661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1320580631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660290330 + 660290331.

It is an arithmetic number, because the mean of its divisors is an integer number (660290331).

Almost surely, 2^1320580661 is an apocalyptic number.

It is an amenable number.

1320580661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320580661 is an equidigital number, since it uses as much as digits as its factorization.

1320580661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 1320580661 is about 36339.7944545645. The cubic root of 1320580661 is about 1097.1221360611.

The spelling of 1320580661 in words is "one billion, three hundred twenty million, five hundred eighty thousand, six hundred sixty-one".