647855 has 8 divisors (see below), whose sum is σ = 837312. Its totient is φ = 478368.

The previous prime is 647851. The next prime is 647861. The reversal of 647855 is 558746.

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

It is a cyclic number.

It is not a de Polignac number, because 647855 - 2² = 647851 is a prime.

It is a super-2 number, since 2×647855² = 839432202050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647855.

It is not an unprimeable number, because it can be changed into a prime (647851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4919 + ... + 5048.

It is an arithmetic number, because the mean of its divisors is an integer number (104664).

2⁶⁴⁷⁸⁵⁵ is an apocalyptic number.

647855 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

647855 is a deficient number, since it is larger than the sum of its proper divisors (189457).

647855 is a wasteful number, since it uses less digits than its factorization.

647855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9985.

The product of its digits is 33600, while the sum is 35.

The square root of 647855 is about 804.8944030120. The cubic root of 647855 is about 86.5285192250.

The spelling of 647855 in words is "six hundred forty-seven thousand, eight hundred fifty-five".