1173640561 has 2 divisors, whose sum is σ = 1173640562. Its totient is φ = 1173640560.

The previous prime is 1173640537. The next prime is 1173640591. The reversal of 1173640561 is 1650463711.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1047752161 + 125888400 = 32369^2 + 11220^2 .

It is a cyclic number.

It is not a de Polignac number, because 1173640561 - 2⁹ = 1173640049 is a prime.

It is not a weakly prime, because it can be changed into another prime (1173640591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 586820280 + 586820281.

It is an arithmetic number, because the mean of its divisors is an integer number (586820281).

Almost surely, 2^1173640561 is an apocalyptic number.

It is an amenable number.

1173640561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1173640561 is an equidigital number, since it uses as much as digits as its factorization.

1173640561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 1173640561 is about 34258.4378073490. The cubic root of 1173640561 is about 1054.8200350396.

The spelling of 1173640561 in words is "one billion, one hundred seventy-three million, six hundred forty thousand, five hundred sixty-one".