1205640263 has 2 divisors, whose sum is σ = 1205640264. Its totient is φ = 1205640262.

The previous prime is 1205640259. The next prime is 1205640283. The reversal of 1205640263 is 3620465021.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1205640263 - 2² = 1205640259 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1205640203) 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, 602820131 + 602820132.

It is an arithmetic number, because the mean of its divisors is an integer number (602820132).

Almost surely, 2^1205640263 is an apocalyptic number.

1205640263 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205640263 is an equidigital number, since it uses as much as digits as its factorization.

1205640263 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 1205640263 is about 34722.3308981410. The cubic root of 1205640263 is about 1064.3208768845.

The spelling of 1205640263 in words is "one billion, two hundred five million, six hundred forty thousand, two hundred sixty-three".