1399640 has 32 divisors (see below), whose sum is σ = 3436560. Its totient is φ = 508800.

The previous prime is 1399639. The next prime is 1399663. The reversal of 1399640 is 469931.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 1399597 and 1399606.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1151 + ... + 2030.

2^1399640 is an apocalyptic number.

1399640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1399640 is an abundant number, since it is smaller than the sum of its proper divisors (2036920).

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

1399640 is a wasteful number, since it uses less digits than its factorization.

1399640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3203 (or 3199 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 1399640 is about 1183.0638190732. The cubic root of 1399640 is about 111.8593046238.

It can be divided in two parts, 139 and 9640, that added together give a palindrome (9779).

The spelling of 1399640 in words is "one million, three hundred ninety-nine thousand, six hundred forty".