1440257869 has 4 divisors (see below), whose sum is σ = 1449431644. Its totient is φ = 1431084096.

The previous prime is 1440257857. The next prime is 1440257911. The reversal of 1440257869 is 9687520441.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9687520441 = 29 ⋅334052429.

It can be written as a sum of positive squares in 2 ways, for example, as 882684100 + 557573769 = 29710^2 + 23613^2 .

It is a cyclic number.

It is not a de Polignac number, because 1440257869 - 2⁵ = 1440257837 is a prime.

It is a super-2 number, since 2×1440257869² = 4148685458432842322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1440257839) 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, 4586652 + ... + 4586965.

It is an arithmetic number, because the mean of its divisors is an integer number (362357911).

Almost surely, 2^1440257869 is an apocalyptic number.

It is an amenable number.

1440257869 is a deficient number, since it is larger than the sum of its proper divisors (9173775).

1440257869 is an equidigital number, since it uses as much as digits as its factorization.

1440257869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9173774.

The product of its (nonzero) digits is 483840, while the sum is 46.

The square root of 1440257869 is about 37950.7294923299. The cubic root of 1440257869 is about 1129.3106373061.

The spelling of 1440257869 in words is "one billion, four hundred forty million, two hundred fifty-seven thousand, eight hundred sixty-nine".