660720 has 40 divisors (see below), whose sum is σ = 2048976. Its totient is φ = 176128.

The previous prime is 660719. The next prime is 660727. The reversal of 660720 is 27066.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1137 + ... + 1616.

2⁶⁶⁰⁷²⁰ is an apocalyptic number.

660720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

660720 is an abundant number, since it is smaller than the sum of its proper divisors (1388256).

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

660720 is a wasteful number, since it uses less digits than its factorization.

660720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2769 (or 2763 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 660720 is about 812.8468490435. The cubic root of 660720 is about 87.0975257247.

Adding to 660720 its reverse (27066), we get a palindrome (687786).

It can be divided in two parts, 6 and 60720, that added together give a triangular number (60726 = T₃₄₈).

The spelling of 660720 in words is "six hundred sixty thousand, seven hundred twenty".