671609815 has 24 divisors (see below), whose sum is σ = 854342208. Its totient is φ = 506761920.

The previous prime is 671609801. The next prime is 671609833. The reversal of 671609815 is 518906176.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-671609815 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 488469 + ... + 489841.

It is an arithmetic number, because the mean of its divisors is an integer number (35597592).

Almost surely, 2^671609815 is an apocalyptic number.

671609815 is a deficient number, since it is larger than the sum of its proper divisors (182732393).

671609815 is a wasteful number, since it uses less digits than its factorization.

671609815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1687 (or 1668 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 671609815 is about 25915.4358442994. The cubic root of 671609815 is about 875.7342690971.

The spelling of 671609815 in words is "six hundred seventy-one million, six hundred nine thousand, eight hundred fifteen".