671641 has 4 divisors (see below), whose sum is σ = 673972. Its totient is φ = 669312.

The previous prime is 671633. The next prime is 671647. The reversal of 671641 is 146176.

671641 = 579² + 580².

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 336400 + 335241 = 580^2 + 579^2 .

It is a cyclic number.

It is not a de Polignac number, because 671641 - 2³ = 671633 is a prime.

It is a super-2 number, since 2×671641² = 902203265762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 660 + ... + 1333.

It is an arithmetic number, because the mean of its divisors is an integer number (168493).

2⁶⁷¹⁶⁴¹ is an apocalyptic number.

671641 is the 580-th centered square number.

It is an amenable number.

671641 is a deficient number, since it is larger than the sum of its proper divisors (2331).

671641 is a wasteful number, since it uses less digits than its factorization.

671641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2330.

The product of its digits is 1008, while the sum is 25.

The square root of 671641 is about 819.5370644455. The cubic root of 671641 is about 87.5747823272.

The spelling of 671641 in words is "six hundred seventy-one thousand, six hundred forty-one".