1261990303 has 18 divisors (see below), whose sum is σ = 1496956344. Its totient is φ = 1042150032.

The previous prime is 1261990267. The next prime is 1261990307. The reversal of 1261990303 is 3030991621.

It is not a de Polignac number, because 1261990303 - 2⁹ = 1261989791 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261990307) 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 in 17 ways as a sum of consecutive naturals, for example, 2725450 + ... + 2725912.

Almost surely, 2^1261990303 is an apocalyptic number.

1261990303 is a deficient number, since it is larger than the sum of its proper divisors (234966041).

1261990303 is an frugal number, since it uses more digits than its factorization.

1261990303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991 (or 499 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 34.

The square root of 1261990303 is about 35524.5028536643. The cubic root of 1261990303 is about 1080.6507004095.

The spelling of 1261990303 in words is "one billion, two hundred sixty-one million, nine hundred ninety thousand, three hundred three".