1440257851 has 4 divisors (see below), whose sum is σ = 1451598592. Its totient is φ = 1428917112.

The previous prime is 1440257849. The next prime is 1440257857. The reversal of 1440257851 is 1587520441.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1587520441 = 13 ⋅122116957.

It is a cyclic number.

It is not a de Polignac number, because 1440257851 - 2¹ = 1440257849 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1440257851.

It is not an unprimeable number, because it can be changed into a prime (1440257857) 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, 5670180 + ... + 5670433.

It is an arithmetic number, because the mean of its divisors is an integer number (362899648).

Almost surely, 2^1440257851 is an apocalyptic number.

1440257851 is a deficient number, since it is larger than the sum of its proper divisors (11340741).

1440257851 is a wasteful number, since it uses less digits than its factorization.

1440257851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11340740.

The product of its (nonzero) digits is 44800, while the sum is 37.

The square root of 1440257851 is about 37950.7292551803. The cubic root of 1440257851 is about 1129.3106326015.

The spelling of 1440257851 in words is "one billion, four hundred forty million, two hundred fifty-seven thousand, eight hundred fifty-one".