1340442121 has 4 divisors (see below), whose sum is σ = 1362416644. Its totient is φ = 1318467600.

The previous prime is 1340442109. The next prime is 1340442137. The reversal of 1340442121 is 1212440431.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1212440431 = 233 ⋅5203607.

It can be written as a sum of positive squares in 2 ways, for example, as 84732025 + 1255710096 = 9205^2 + 35436^2 .

It is a cyclic number.

It is not a de Polignac number, because 1340442121 - 2²⁵ = 1306887689 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1340442092 and 1340442101.

It is not an unprimeable number, because it can be changed into a prime (1340442421) 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, 10987170 + ... + 10987291.

It is an arithmetic number, because the mean of its divisors is an integer number (340604161).

Almost surely, 2^1340442121 is an apocalyptic number.

It is an amenable number.

1340442121 is a deficient number, since it is larger than the sum of its proper divisors (21974523).

1340442121 is an equidigital number, since it uses as much as digits as its factorization.

1340442121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21974522.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 1340442121 is about 36612.0488500712. The cubic root of 1340442121 is about 1102.5950085663.

Adding to 1340442121 its reverse (1212440431), we get a palindrome (2552882552).

The spelling of 1340442121 in words is "one billion, three hundred forty million, four hundred forty-two thousand, one hundred twenty-one".