1311115501 has 4 divisors (see below), whose sum is σ = 1380121600. Its totient is φ = 1242109404.

The previous prime is 1311115493. The next prime is 1311115567. The reversal of 1311115501 is 1055111131.

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 a cyclic number.

It is not a de Polignac number, because 1311115501 - 2³ = 1311115493 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 69006079 = 1311115501 / (1 + 3 + 1 + 1 + 1 + 1 + 5 + 5 + 0 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311115571) 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, 34503021 + ... + 34503058.

It is an arithmetic number, because the mean of its divisors is an integer number (345030400).

Almost surely, 2^1311115501 is an apocalyptic number.

It is an amenable number.

1311115501 is a deficient number, since it is larger than the sum of its proper divisors (69006099).

1311115501 is an equidigital number, since it uses as much as digits as its factorization.

1311115501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69006098.

The product of its (nonzero) digits is 75, while the sum is 19.

The square root of 1311115501 is about 36209.3289222543. The cubic root of 1311115501 is about 1094.4946692171.

Adding to 1311115501 its reverse (1055111131), we get a palindrome (2366226632).

The spelling of 1311115501 in words is "one billion, three hundred eleven million, one hundred fifteen thousand, five hundred one".