1260636661 has 2 divisors, whose sum is σ = 1260636662. Its totient is φ = 1260636660.

The previous prime is 1260636659. The next prime is 1260636667. The reversal of 1260636661 is 1666360621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1171692900 + 88943761 = 34230^2 + 9431^2 .

It is a cyclic number.

It is not a de Polignac number, because 1260636661 - 2¹ = 1260636659 is a prime.

Together with 1260636659, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1260636661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1260636667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630318330 + 630318331.

It is an arithmetic number, because the mean of its divisors is an integer number (630318331).

Almost surely, 2^1260636661 is an apocalyptic number.

It is an amenable number.

1260636661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1260636661 is an equidigital number, since it uses as much as digits as its factorization.

1260636661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 1260636661 is about 35505.4455119211. The cubic root of 1260636661 is about 1080.2641846281.

The spelling of 1260636661 in words is "one billion, two hundred sixty million, six hundred thirty-six thousand, six hundred sixty-one".