1205640763 has 4 divisors (see below), whose sum is σ = 1269095560. Its totient is φ = 1142185968.

The previous prime is 1205640727. The next prime is 1205640773. The reversal of 1205640763 is 3670465021.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1205640763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1205640773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31727370 + ... + 31727407.

It is an arithmetic number, because the mean of its divisors is an integer number (317273890).

Almost surely, 2^1205640763 is an apocalyptic number.

1205640763 is a deficient number, since it is larger than the sum of its proper divisors (63454797).

1205640763 is an equidigital number, since it uses as much as digits as its factorization.

1205640763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63454796.

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 1205640763 is about 34722.3380981178. The cubic root of 1205640763 is about 1064.3210240153.

The spelling of 1205640763 in words is "one billion, two hundred five million, six hundred forty thousand, seven hundred sixty-three".