671812641 has 6 divisors (see below), whose sum is σ = 970396050. Its totient is φ = 447875088.

The previous prime is 671812639. The next prime is 671812651. The reversal of 671812641 is 146218176.

It is a happy number.

671812641 is a `hidden beast` number, since 6 + 7 + 1 + 8 + 1 + 2 + 641 = 666.

It can be written as a sum of positive squares in only one way, i.e., 467208225 + 204604416 = 21615^2 + 14304^2 .

It is not a de Polignac number, because 671812641 - 2¹ = 671812639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 671812596 and 671812605.

It is not an unprimeable number, because it can be changed into a prime (671812651) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37322916 + ... + 37322933.

It is an arithmetic number, because the mean of its divisors is an integer number (161732675).

Almost surely, 2^671812641 is an apocalyptic number.

It is an amenable number.

671812641 is a deficient number, since it is larger than the sum of its proper divisors (298583409).

671812641 is a wasteful number, since it uses less digits than its factorization.

671812641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74645855 (or 74645852 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 671812641 is about 25919.3487765414. The cubic root of 671812641 is about 875.8224174026.

The spelling of 671812641 in words is "six hundred seventy-one million, eight hundred twelve thousand, six hundred forty-one".