1440890309 has 4 divisors (see below), whose sum is σ = 1443849504. Its totient is φ = 1437931116.

The previous prime is 1440890287. The next prime is 1440890357. The reversal of 1440890309 is 9030980441.

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: 9030980441 = 7 ⋅1290140063.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1440890309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1440892309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1478867 + ... + 1479840.

It is an arithmetic number, because the mean of its divisors is an integer number (360962376).

Almost surely, 2^1440890309 is an apocalyptic number.

It is an amenable number.

1440890309 is a deficient number, since it is larger than the sum of its proper divisors (2959195).

1440890309 is an equidigital number, since it uses as much as digits as its factorization.

1440890309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2959194.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 1440890309 is about 37959.0609604611. The cubic root of 1440890309 is about 1129.4759125017.

The spelling of 1440890309 in words is "one billion, four hundred forty million, eight hundred ninety thousand, three hundred nine".