1313388561 has 4 divisors (see below), whose sum is σ = 1751184752. Its totient is φ = 875592372.

The previous prime is 1313388553. The next prime is 1313388589. The reversal of 1313388561 is 1658833131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1313388561 - 2³ = 1313388553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1313388541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218898091 + ... + 218898096.

It is an arithmetic number, because the mean of its divisors is an integer number (437796188).

Almost surely, 2^1313388561 is an apocalyptic number.

It is an amenable number.

1313388561 is a deficient number, since it is larger than the sum of its proper divisors (437796191).

1313388561 is an equidigital number, since it uses as much as digits as its factorization.

1313388561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437796190.

The product of its digits is 51840, while the sum is 39.

The square root of 1313388561 is about 36240.7030974842. The cubic root of 1313388561 is about 1095.1268066903.

The spelling of 1313388561 in words is "one billion, three hundred thirteen million, three hundred eighty-eight thousand, five hundred sixty-one".