1311200005 has 4 divisors (see below), whose sum is σ = 1573440012. Its totient is φ = 1048960000.

The previous prime is 1311200003. The next prime is 1311200041. The reversal of 1311200005 is 5000021131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5000021131 = 7 ⋅714288733.

It can be written as a sum of positive squares in 2 ways, for example, as 571305604 + 739894401 = 23902^2 + 27201^2 .

It is not a de Polignac number, because 1311200005 - 2¹ = 1311200003 is a prime.

It is a super-2 number, since 2×1311200005² = 3438490906224000050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311200003) 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, 131119996 + ... + 131120005.

It is an arithmetic number, because the mean of its divisors is an integer number (393360003).

Almost surely, 2^1311200005 is an apocalyptic number.

It is an amenable number.

1311200005 is a deficient number, since it is larger than the sum of its proper divisors (262240007).

1311200005 is an equidigital number, since it uses as much as digits as its factorization.

1311200005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262240006.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 1311200005 is about 36210.4957850621. The cubic root of 1311200005 is about 1094.5181828309.

Adding to 1311200005 its reverse (5000021131), we get a palindrome (6311221136).

The spelling of 1311200005 in words is "one billion, three hundred eleven million, two hundred thousand, five".