1313521777 has 4 divisors (see below), whose sum is σ = 1331515300. Its totient is φ = 1295528256.

The previous prime is 1313521763. The next prime is 1313521799. The reversal of 1313521777 is 7771253131.

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 808890481 + 504631296 = 28441^2 + 22464^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1313521777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1313521747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8996652 + ... + 8996797.

It is an arithmetic number, because the mean of its divisors is an integer number (332878825).

Almost surely, 2^1313521777 is an apocalyptic number.

It is an amenable number.

1313521777 is a deficient number, since it is larger than the sum of its proper divisors (17993523).

1313521777 is an equidigital number, since it uses as much as digits as its factorization.

1313521777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17993522.

The product of its digits is 30870, while the sum is 37.

The square root of 1313521777 is about 36242.5409843184. The cubic root of 1313521777 is about 1095.1638313974.

The spelling of 1313521777 in words is "one billion, three hundred thirteen million, five hundred twenty-one thousand, seven hundred seventy-seven".