647828 has 6 divisors (see below), whose sum is σ = 1133706. Its totient is φ = 323912.

The previous prime is 647821. The next prime is 647837. The reversal of 647828 is 828746.

It can be written as a sum of positive squares in only one way, i.e., 643204 + 4624 = 802^2 + 68^2 .

It is a super-2 number, since 2×647828² = 839362235168, which contains 22 as substring.

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 647828.

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 as a sum of consecutive naturals, namely, 80975 + ... + 80982.

It is an arithmetic number, because the mean of its divisors is an integer number (188951).

2⁶⁴⁷⁸²⁸ is an apocalyptic number.

It is an amenable number.

647828 is a deficient number, since it is larger than the sum of its proper divisors (485878).

647828 is a wasteful number, since it uses less digits than its factorization.

647828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161961 (or 161959 counting only the distinct ones).

The product of its digits is 21504, while the sum is 35.

The square root of 647828 is about 804.8776304507. The cubic root of 647828 is about 86.5273171543.

The spelling of 647828 in words is "six hundred forty-seven thousand, eight hundred twenty-eight".