1313561551 has 4 divisors (see below), whose sum is σ = 1314096472. Its totient is φ = 1313026632.

The previous prime is 1313561521. The next prime is 1313561621. The reversal of 1313561551 is 1551653131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1551653131 = 7 ⋅221664733.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1313561551 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 (1313561521) 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, 263760 + ... + 268693.

It is an arithmetic number, because the mean of its divisors is an integer number (328524118).

Almost surely, 2^1313561551 is an apocalyptic number.

1313561551 is a deficient number, since it is larger than the sum of its proper divisors (534921).

1313561551 is an equidigital number, since it uses as much as digits as its factorization.

1313561551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534920.

The product of its digits is 6750, while the sum is 31.

The square root of 1313561551 is about 36243.0896999690. The cubic root of 1313561551 is about 1095.1748852952.

The spelling of 1313561551 in words is "one billion, three hundred thirteen million, five hundred sixty-one thousand, five hundred fifty-one".