1399440 has 160 divisors (see below), whose sum is σ = 5356800. Its totient is φ = 301056.

The previous prime is 1399439. The next prime is 1399441. The reversal of 1399440 is 449931.

1399440 is nontrivially palindromic in base 13.

It is an interprime number because it is at equal distance from previous prime (1399439) and next prime (1399441).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1399398 and 1399407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1399441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 82312 + ... + 82328.

It is an arithmetic number, because the mean of its divisors is an integer number (33480).

2^1399440 is an apocalyptic number.

1399440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1399440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2678400).

1399440 is an abundant number, since it is smaller than the sum of its proper divisors (3957360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1399440 is a wasteful number, since it uses less digits than its factorization.

1399440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54 (or 34 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 1399440 is about 1182.9792897595. The cubic root of 1399440 is about 111.8539763664.

The spelling of 1399440 in words is "one million, three hundred ninety-nine thousand, four hundred forty".