1311261506 has 8 divisors (see below), whose sum is σ = 2034716220. Its totient is φ = 633022768.

The previous prime is 1311261503. The next prime is 1311261509. The reversal of 1311261506 is 6051621131.

It is an interprime number because it is at equal distance from previous prime (1311261503) and next prime (1311261509).

It can be written as a sum of positive squares in 2 ways, for example, as 1306461025 + 4800481 = 36145^2 + 2191^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1311261503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11303921 + ... + 11304036.

Almost surely, 2^1311261506 is an apocalyptic number.

1311261506 is a deficient number, since it is larger than the sum of its proper divisors (723454714).

1311261506 is a wasteful number, since it uses less digits than its factorization.

1311261506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22607988.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 1311261506 is about 36211.3449902099. The cubic root of 1311261506 is about 1094.5352951224.

Adding to 1311261506 its reverse (6051621131), we get a palindrome (7362882637).

The spelling of 1311261506 in words is "one billion, three hundred eleven million, two hundred sixty-one thousand, five hundred six".