1814440721 has 4 divisors (see below), whose sum is σ = 1893329472. Its totient is φ = 1735551972.

The previous prime is 1814440717. The next prime is 1814440751. The reversal of 1814440721 is 1270444181.

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: 1270444181 = 12781 ⋅99401.

It is a cyclic number.

It is not a de Polignac number, because 1814440721 - 2² = 1814440717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1814440711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39444341 + ... + 39444386.

It is an arithmetic number, because the mean of its divisors is an integer number (473332368).

Almost surely, 2^1814440721 is an apocalyptic number.

It is an amenable number.

1814440721 is a deficient number, since it is larger than the sum of its proper divisors (78888751).

1814440721 is an equidigital number, since it uses as much as digits as its factorization.

1814440721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78888750.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 1814440721 is about 42596.2524290577. The cubic root of 1814440721 is about 1219.6847525972.

The spelling of 1814440721 in words is "one billion, eight hundred fourteen million, four hundred forty thousand, seven hundred twenty-one".