671878849 has 4 divisors (see below), whose sum is σ = 688266180. Its totient is φ = 655491520.

The previous prime is 671878807. The next prime is 671878859. The reversal of 671878849 is 948878176.

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 91068849 + 580810000 = 9543^2 + 24100^2 .

It is a cyclic number.

It is not a de Polignac number, because 671878849 - 2¹¹ = 671876801 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 671878793 and 671878802.

It is not an unprimeable number, because it can be changed into a prime (671878859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8193604 + ... + 8193685.

It is an arithmetic number, because the mean of its divisors is an integer number (172066545).

Almost surely, 2^671878849 is an apocalyptic number.

It is an amenable number.

671878849 is a deficient number, since it is larger than the sum of its proper divisors (16387331).

671878849 is a wasteful number, since it uses less digits than its factorization.

671878849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16387330.

The product of its digits is 5419008, while the sum is 58.

The square root of 671878849 is about 25920.6259376582. The cubic root of 671878849 is about 875.8511875994.

The spelling of 671878849 in words is "six hundred seventy-one million, eight hundred seventy-eight thousand, eight hundred forty-nine".