671819405 has 4 divisors (see below), whose sum is σ = 806183292. Its totient is φ = 537455520.

The previous prime is 671819341. The next prime is 671819411. The reversal of 671819405 is 504918176.

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 499343716 + 172475689 = 22346^2 + 13133^2 .

It is not a de Polignac number, because 671819405 - 2⁶ = 671819341 is a prime.

It is a Duffinian number.

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, 67181936 + ... + 67181945.

It is an arithmetic number, because the mean of its divisors is an integer number (201545823).

Almost surely, 2^671819405 is an apocalyptic number.

It is an amenable number.

671819405 is a deficient number, since it is larger than the sum of its proper divisors (134363887).

671819405 is a wasteful number, since it uses less digits than its factorization.

671819405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134363886.

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 671819405 is about 25919.4792578863. The cubic root of 671819405 is about 875.8253567354.

The spelling of 671819405 in words is "six hundred seventy-one million, eight hundred nineteen thousand, four hundred five".