1399680 has 128 divisors (see below), whose sum is σ = 5018400. Its totient is φ = 373248.

The previous prime is 1399679. The next prime is 1399687. The reversal of 1399680 is 869931.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 6.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1399687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 279934 + ... + 279938.

2^1399680 is an apocalyptic number.

1399680 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 1399680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2509200).

1399680 is an abundant number, since it is smaller than the sum of its proper divisors (3618720).

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

1399680 is an frugal number, since it uses more digits than its factorization.

1399680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40 (or 10 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 1399680 is about 1183.0807242112. The cubic root of 1399680 is about 111.8603702143.

Adding to 1399680 its product of nonzero digits (11664), we get a square (1411344 = 1188²).

1399680 divided by its product of nonzero digits (11664) gives a triangular number (120 = T₁₅).

The spelling of 1399680 in words is "one million, three hundred ninety-nine thousand, six hundred eighty".