65720 has 32 divisors (see below), whose sum is σ = 155520. Its totient is φ = 24960.

The previous prime is 65719. The next prime is 65729. The reversal of 65720 is 2756.

65720 = T₄₉ + T₅₀ + ... + T₇₉.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 65692 and 65701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1214 + ... + 1266.

It is an arithmetic number, because the mean of its divisors is an integer number (4860).

2⁶⁵⁷²⁰ 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 65720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77760).

65720 is an abundant number, since it is smaller than the sum of its proper divisors (89800).

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

65720 is a wasteful number, since it uses less digits than its factorization.

65720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95 (or 91 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 65720 is about 256.3591231066. The cubic root of 65720 is about 40.3551703499.

The spelling of 65720 in words is "sixty-five thousand, seven hundred twenty".