671794561 has 3 divisors (see below), whose sum is σ = 671820481. Its totient is φ = 671768642.

The previous prime is 671794537. The next prime is 671794589. The reversal of 671794561 is 165497176.

The square root of 671794561 is 25919.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 671794561 - 2¹⁵ = 671761793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671794961) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 12960 + ... + 38878.

Almost surely, 2^671794561 is an apocalyptic number.

671794561 is the 25919-th square number.

671794561 is the 12960-th centered octagonal number.

It is an amenable number.

671794561 is a deficient number, since it is larger than the sum of its proper divisors (25920).

671794561 is an frugal number, since it uses more digits than its factorization.

671794561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51838 (or 25919 counting only the distinct ones).

The product of its digits is 317520, while the sum is 46.

The cubic root of 671794561 is about 875.8145605437.

The spelling of 671794561 in words is "six hundred seventy-one million, seven hundred ninety-four thousand, five hundred sixty-one".