647209028 has 6 divisors (see below), whose sum is σ = 1132615806. Its totient is φ = 323604512.

The previous prime is 647209009. The next prime is 647209051. The reversal of 647209028 is 820902746.

It can be written as a sum of positive squares in only one way, i.e., 340328704 + 306880324 = 18448^2 + 17518^2 .

It is a junction number, because it is equal to n+sod(n) for n = 647208982 and 647209000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80901125 + ... + 80901132.

It is an arithmetic number, because the mean of its divisors is an integer number (188769301).

Almost surely, 2^647209028 is an apocalyptic number.

It is an amenable number.

647209028 is a deficient number, since it is larger than the sum of its proper divisors (485406778).

647209028 is a wasteful number, since it uses less digits than its factorization.

647209028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161802261 (or 161802259 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 647209028 is about 25440.3032214634. The cubic root of 647209028 is about 864.9975065361.

The spelling of 647209028 in words is "six hundred forty-seven million, two hundred nine thousand, twenty-eight".