631645 has 8 divisors (see below), whose sum is σ = 866304. Its totient is φ = 433104.

The previous prime is 631643. The next prime is 631667. The reversal of 631645 is 546136.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 631645 - 2¹ = 631643 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8989 + ... + 9058.

It is an arithmetic number, because the mean of its divisors is an integer number (108288).

2⁶³¹⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

631645 is a deficient number, since it is larger than the sum of its proper divisors (234659).

631645 is a wasteful number, since it uses less digits than its factorization.

631645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18059.

The product of its digits is 2160, while the sum is 25.

The square root of 631645 is about 794.7609703552. The cubic root of 631645 is about 85.8007375105.

The spelling of 631645 in words is "six hundred thirty-one thousand, six hundred forty-five".