671841561 has 16 divisors (see below), whose sum is σ = 904149504. Its totient is φ = 443727744.

The previous prime is 671841559. The next prime is 671841587. The reversal of 671841561 is 165148176.

It is not a de Polignac number, because 671841561 - 2¹ = 671841559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (671846561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 248131 + ... + 250823.

It is an arithmetic number, because the mean of its divisors is an integer number (56509344).

Almost surely, 2^671841561 is an apocalyptic number.

It is an amenable number.

671841561 is a deficient number, since it is larger than the sum of its proper divisors (232307943).

671841561 is a wasteful number, since it uses less digits than its factorization.

671841561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3440.

The product of its digits is 40320, while the sum is 39.

The square root of 671841561 is about 25919.9066549245. The cubic root of 671841561 is about 875.8349846072.

The spelling of 671841561 in words is "six hundred seventy-one million, eight hundred forty-one thousand, five hundred sixty-one".