1231020113 has 4 divisors (see below), whose sum is σ = 1243711140. Its totient is φ = 1218329088.

The previous prime is 1231020103. The next prime is 1231020139. The reversal of 1231020113 is 3110201321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3110201321 = 367 ⋅8474663.

It can be written as a sum of positive squares in 2 ways, for example, as 930067009 + 300953104 = 30497^2 + 17348^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231020113 - 2²⁰ = 1229971537 is a prime.

It is a super-2 number, since 2×1231020113² = 3030821037221065538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231020103) 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, 6345368 + ... + 6345561.

It is an arithmetic number, because the mean of its divisors is an integer number (310927785).

Almost surely, 2^1231020113 is an apocalyptic number.

It is an amenable number.

1231020113 is a deficient number, since it is larger than the sum of its proper divisors (12691027).

1231020113 is an equidigital number, since it uses as much as digits as its factorization.

1231020113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12691026.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 1231020113 is about 35085.8962120109. The cubic root of 1231020113 is about 1071.7373914106.

Adding to 1231020113 its reverse (3110201321), we get a palindrome (4341221434).

It can be divided in two parts, 12310 and 20113, that added together give a palindrome (32423).

The spelling of 1231020113 in words is "one billion, two hundred thirty-one million, twenty thousand, one hundred thirteen".