647842 has 8 divisors (see below), whose sum is σ = 1046556. Its totient is φ = 298992.

The previous prime is 647839. The next prime is 647851. The reversal of 647842 is 248746.

It can be written as a sum of positive squares in 2 ways, for example, as 641601 + 6241 = 801^2 + 79^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 12433 + ... + 12484.

2⁶⁴⁷⁸⁴² is an apocalyptic number.

647842 is a deficient number, since it is larger than the sum of its proper divisors (398714).

647842 is a wasteful number, since it uses less digits than its factorization.

647842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24932.

The product of its digits is 10752, while the sum is 31.

The square root of 647842 is about 804.8863273780. The cubic root of 647842 is about 86.5279404544.

The spelling of 647842 in words is "six hundred forty-seven thousand, eight hundred forty-two".