631720 has 32 divisors (see below), whose sum is σ = 1506600. Its totient is φ = 237568.

The previous prime is 631717. The next prime is 631723. The reversal of 631720 is 27136.

It is an interprime number because it is at equal distance from previous prime (631717) and next prime (631723).

It can be written as a sum of positive squares in 4 ways, for example, as 407044 + 224676 = 638^2 + 474^2 .

It is not an unprimeable number, because it can be changed into a prime (631723) 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, 216 + ... + 1144.

2⁶³¹⁷²⁰ 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 631720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (753300).

631720 is an abundant number, since it is smaller than the sum of its proper divisors (874880).

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

631720 is a wasteful number, since it uses less digits than its factorization.

631720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 957 (or 953 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 631720 is about 794.8081529526. The cubic root of 631720 is about 85.8041333001.

Adding to 631720 its reverse (27136), we get a palindrome (658856).

The spelling of 631720 in words is "six hundred thirty-one thousand, seven hundred twenty".