1240404121 has 4 divisors (see below), whose sum is σ = 1353168144. Its totient is φ = 1127640100.

The previous prime is 1240404107. The next prime is 1240404149. The reversal of 1240404121 is 1214040421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1214040421 = 11 ⋅110367311.

It is a cyclic number.

It is not a de Polignac number, because 1240404121 - 2⁵ = 1240404089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1240404161) 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, 56381995 + ... + 56382016.

It is an arithmetic number, because the mean of its divisors is an integer number (338292036).

Almost surely, 2^1240404121 is an apocalyptic number.

1240404121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1240404121 is a deficient number, since it is larger than the sum of its proper divisors (112764023).

1240404121 is a wasteful number, since it uses less digits than its factorization.

1240404121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112764022.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 1240404121 is about 35219.3713884845. The cubic root of 1240404121 is about 1074.4537685736.

Adding to 1240404121 its reverse (1214040421), we get a palindrome (2454444542).

The spelling of 1240404121 in words is "one billion, two hundred forty million, four hundred four thousand, one hundred twenty-one".