671690 has 8 divisors (see below), whose sum is σ = 1209060. Its totient is φ = 268672.

The previous prime is 671681. The next prime is 671701. The reversal of 671690 is 96176.

It is a happy number.

671690 is nontrivially palindromic in base 4.

It can be written as a sum of positive squares in 2 ways, for example, as 635209 + 36481 = 797^2 + 191^2 .

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

It is a super-2 number, since 2×671690² = 902334912200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33575 + ... + 33594.

2⁶⁷¹⁶⁹⁰ is an apocalyptic number.

671690 is a deficient number, since it is larger than the sum of its proper divisors (537370).

671690 is a wasteful number, since it uses less digits than its factorization.

671690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67176.

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 671690 is about 819.5669588264. The cubic root of 671690 is about 87.5769119669.

The spelling of 671690 in words is "six hundred seventy-one thousand, six hundred ninety".