1231021423 has 4 divisors (see below), whose sum is σ = 1231091680. Its totient is φ = 1230951168.

The previous prime is 1231021409. The next prime is 1231021453. The reversal of 1231021423 is 3241201321.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3241201321 = 149 ⋅21753029.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231021423 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231021423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231021403) 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, 14986 + ... + 51832.

It is an arithmetic number, because the mean of its divisors is an integer number (307772920).

Almost surely, 2^1231021423 is an apocalyptic number.

1231021423 is a deficient number, since it is larger than the sum of its proper divisors (70257).

1231021423 is an equidigital number, since it uses as much as digits as its factorization.

1231021423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70256.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 1231021423 is about 35085.9148804759. The cubic root of 1231021423 is about 1071.7377715764.

Adding to 1231021423 its reverse (3241201321), we get a palindrome (4472222744).

It can be divided in two parts, 12310 and 21423, that added together give a palindrome (33733).

The spelling of 1231021423 in words is "one billion, two hundred thirty-one million, twenty-one thousand, four hundred twenty-three".