1320634657 has 2 divisors, whose sum is σ = 1320634658. Its totient is φ = 1320634656.

The previous prime is 1320634621. The next prime is 1320634669. The reversal of 1320634657 is 7564360231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 746600976 + 574033681 = 27324^2 + 23959^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320634657 is a prime.

It is not a weakly prime, because it can be changed into another prime (1320634607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660317328 + 660317329.

It is an arithmetic number, because the mean of its divisors is an integer number (660317329).

Almost surely, 2^1320634657 is an apocalyptic number.

It is an amenable number.

1320634657 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320634657 is an equidigital number, since it uses as much as digits as its factorization.

1320634657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 37.

The square root of 1320634657 is about 36340.5373790757. The cubic root of 1320634657 is about 1097.1370889278.

Adding to 1320634657 its reverse (7564360231), we get a palindrome (8884994888).

The spelling of 1320634657 in words is "one billion, three hundred twenty million, six hundred thirty-four thousand, six hundred fifty-seven".