1231443109 has 4 divisors (see below), whose sum is σ = 1326169516. Its totient is φ = 1136716704.

The previous prime is 1231443107. The next prime is 1231443119. The reversal of 1231443109 is 9013441321.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 621106084 + 610337025 = 24922^2 + 24705^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231443109 - 2¹ = 1231443107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231443107) 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, 47363184 + ... + 47363209.

It is an arithmetic number, because the mean of its divisors is an integer number (331542379).

Almost surely, 2^1231443109 is an apocalyptic number.

It is an amenable number.

1231443109 is a deficient number, since it is larger than the sum of its proper divisors (94726407).

1231443109 is an equidigital number, since it uses as much as digits as its factorization.

1231443109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94726406.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 1231443109 is about 35091.9237004756. The cubic root of 1231443109 is about 1071.8601320845.

It can be divided in two parts, 123144 and 3109, that added together give a triangular number (126253 = T₅₀₂).

The spelling of 1231443109 in words is "one billion, two hundred thirty-one million, four hundred forty-three thousand, one hundred nine".