1231320013 has 32 divisors (see below), whose sum is σ = 1634750208. Its totient is φ = 897868800.

The previous prime is 1231320011. The next prime is 1231320017. The reversal of 1231320013 is 3100231321.

It is a cyclic number.

It is not a de Polignac number, because 1231320013 - 2¹ = 1231320011 is a prime.

It is a super-2 number, since 2×1231320013² = 3032297948828640338, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231320011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 234331 + ... + 239527.

It is an arithmetic number, because the mean of its divisors is an integer number (51085944).

Almost surely, 2^1231320013 is an apocalyptic number.

It is an amenable number.

1231320013 is a deficient number, since it is larger than the sum of its proper divisors (403430195).

1231320013 is a wasteful number, since it uses less digits than its factorization.

1231320013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5413.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 1231320013 is about 35090.1697488057. The cubic root of 1231320013 is about 1071.8244162401.

Adding to 1231320013 its reverse (3100231321), we get a palindrome (4331551334).

The spelling of 1231320013 in words is "one billion, two hundred thirty-one million, three hundred twenty thousand, thirteen".