647881 has 16 divisors (see below), whose sum is σ = 763840. Its totient is φ = 544320.

The previous prime is 647861. The next prime is 647891. The reversal of 647881 is 188746.

It is a happy number.

647881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 647881 - 2⁷ = 647753 is a prime.

It is a super-2 number, since 2×647881² = 839499580322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10591 + ... + 10651.

It is an arithmetic number, because the mean of its divisors is an integer number (47740).

2⁶⁴⁷⁸⁸¹ is an apocalyptic number.

647881 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

647881 is a deficient number, since it is larger than the sum of its proper divisors (115959).

647881 is a wasteful number, since it uses less digits than its factorization.

647881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136.

The product of its digits is 10752, while the sum is 34.

The square root of 647881 is about 804.9105540369. The cubic root of 647881 is about 86.5296767430.

The spelling of 647881 in words is "six hundred forty-seven thousand, eight hundred eighty-one".