671569 has 4 divisors (see below), whose sum is σ = 673380. Its totient is φ = 669760.

The previous prime is 671557. The next prime is 671581. The reversal of 671569 is 965176.

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

It is an interprime number because it is at equal distance from previous prime (671557) and next prime (671581).

It can be written as a sum of positive squares in 2 ways, for example, as 374544 + 297025 = 612^2 + 545^2 .

It is a cyclic number.

It is not a de Polignac number, because 671569 - 2⁵ = 671537 is a prime.

It is a super-2 number, since 2×671569² = 902009843522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671519) 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 3 ways as a sum of consecutive naturals, for example, 124 + ... + 1165.

It is an arithmetic number, because the mean of its divisors is an integer number (168345).

2⁶⁷¹⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

671569 is a deficient number, since it is larger than the sum of its proper divisors (1811).

671569 is a wasteful number, since it uses less digits than its factorization.

671569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1810.

The product of its digits is 11340, while the sum is 34.

The square root of 671569 is about 819.4931360298. The cubic root of 671569 is about 87.5716528728.

The spelling of 671569 in words is "six hundred seventy-one thousand, five hundred sixty-nine".