671720 has 32 divisors (see below), whose sum is σ = 1728000. Its totient is φ = 230208.

The previous prime is 671717. The next prime is 671729. The reversal of 671720 is 27176.

Added to its reverse (27176) it gives a square (698896 = 836²).

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671729) 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, 920 + ... + 1479.

It is an arithmetic number, because the mean of its divisors is an integer number (54000).

2⁶⁷¹⁷²⁰ is an apocalyptic number.

It is an amenable number.

671720 is an abundant number, since it is smaller than the sum of its proper divisors (1056280).

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

671720 is a wasteful number, since it uses less digits than its factorization.

671720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2417 (or 2413 counting only the distinct ones).

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 671720 is about 819.5852609704. The cubic root of 671720 is about 87.5782157768.

Adding to 671720 its reverse (27176), we get a palindrome (698896).

The spelling of 671720 in words is "six hundred seventy-one thousand, seven hundred twenty".