1399424 has 48 divisors (see below), whose sum is σ = 3109470. Its totient is φ = 623616.

The previous prime is 1399417. The next prime is 1399427. The reversal of 1399424 is 4249931.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1000000 + 399424 = 1000^2 + 632^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a zygodrome in base 4.

It is not an unprimeable number, because it can be changed into a prime (1399427) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 48242 + ... + 48270.

2^1399424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1399424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1554735).

1399424 is an abundant number, since it is smaller than the sum of its proper divisors (1710046).

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

1399424 is an equidigital number, since it uses as much as digits as its factorization.

1399424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 44 counting only the distinct ones).

The product of its digits is 7776, while the sum is 32.

The square root of 1399424 is about 1182.9725271535. The cubic root of 1399424 is about 111.8535500838.

The spelling of 1399424 in words is "one million, three hundred ninety-nine thousand, four hundred twenty-four".