671297805 has 12 divisors (see below), whose sum is σ = 1163582940. Its totient is φ = 358025472.

The previous prime is 671297789. The next prime is 671297807. The reversal of 671297805 is 508792176.

It can be written as a sum of positive squares in 2 ways, for example, as 100040004 + 571257801 = 10002^2 + 23901^2 .

It is not a de Polignac number, because 671297805 - 2⁴ = 671297789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 14917729 = 671297805 / (6 + 7 + 1 + 2 + 9 + 7 + 8 + 0 + 5).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671297807) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7458820 + ... + 7458909.

It is an arithmetic number, because the mean of its divisors is an integer number (96965245).

Almost surely, 2^671297805 is an apocalyptic number.

It is an amenable number.

671297805 is a deficient number, since it is larger than the sum of its proper divisors (492285135).

671297805 is a wasteful number, since it uses less digits than its factorization.

671297805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14917740 (or 14917737 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 45.

The square root of 671297805 is about 25909.4153735664. The cubic root of 671297805 is about 875.5986347020.

The spelling of 671297805 in words is "six hundred seventy-one million, two hundred ninety-seven thousand, eight hundred five".