1311555061 has 4 divisors (see below), whose sum is σ = 1314132300. Its totient is φ = 1308977824.

The previous prime is 1311555019. The next prime is 1311555107. The reversal of 1311555061 is 1605551131.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1089396036 + 222159025 = 33006^2 + 14905^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311555061 - 2⁹ = 1311554549 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 (1311555361) 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, 1287856 + ... + 1288873.

It is an arithmetic number, because the mean of its divisors is an integer number (328533075).

Almost surely, 2^1311555061 is an apocalyptic number.

It is an amenable number.

1311555061 is a deficient number, since it is larger than the sum of its proper divisors (2577239).

1311555061 is an equidigital number, since it uses as much as digits as its factorization.

1311555061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2577238.

The product of its (nonzero) digits is 2250, while the sum is 28.

The square root of 1311555061 is about 36215.3981201367. The cubic root of 1311555061 is about 1094.6169677034.

The spelling of 1311555061 in words is "one billion, three hundred eleven million, five hundred fifty-five thousand, sixty-one".