1311221423 has 4 divisors (see below), whose sum is σ = 1330791960. Its totient is φ = 1291650888.

The previous prime is 1311221419. The next prime is 1311221449. The reversal of 1311221423 is 3241221131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3241221131 = 83 ⋅39050857.

It is a cyclic number.

It is not a de Polignac number, because 1311221423 - 2² = 1311221419 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1311221395 and 1311221404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311221323) 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, 9785168 + ... + 9785301.

It is an arithmetic number, because the mean of its divisors is an integer number (332697990).

Almost surely, 2^1311221423 is an apocalyptic number.

1311221423 is a deficient number, since it is larger than the sum of its proper divisors (19570537).

1311221423 is an equidigital number, since it uses as much as digits as its factorization.

1311221423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19570536.

The product of its digits is 288, while the sum is 20.

The square root of 1311221423 is about 36210.7915268363. The cubic root of 1311221423 is about 1094.5241423241.

Adding to 1311221423 its reverse (3241221131), we get a palindrome (4552442554).

The spelling of 1311221423 in words is "one billion, three hundred eleven million, two hundred twenty-one thousand, four hundred twenty-three".