1660720 has 20 divisors (see below), whose sum is σ = 3861360. Its totient is φ = 664256.

The previous prime is 1660709. The next prime is 1660721. The reversal of 1660720 is 270661.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 1660691 and 1660700.

It is not an unprimeable number, because it can be changed into a prime (1660721) 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, 10300 + ... + 10459.

It is an arithmetic number, because the mean of its divisors is an integer number (193068).

2^1660720 is an apocalyptic number.

1660720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1660720 is an abundant number, since it is smaller than the sum of its proper divisors (2200640).

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

1660720 is a wasteful number, since it uses less digits than its factorization.

1660720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20772 (or 20766 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 1660720 is about 1288.6892565704. The cubic root of 1660720 is about 118.4219310483.

The spelling of 1660720 in words is "one million, six hundred sixty thousand, seven hundred twenty".