647667 has 6 divisors (see below), whose sum is σ = 935532. Its totient is φ = 431772.

The previous prime is 647663. The next prime is 647687. The reversal of 647667 is 766746.

647667 is a `hidden beast` number, since 647 + 6 + 6 + 7 = 666.

It is not a de Polignac number, because 647667 - 2² = 647663 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647667.

It is not an unprimeable number, because it can be changed into a prime (647663) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35973 + ... + 35990.

It is an arithmetic number, because the mean of its divisors is an integer number (155922).

2⁶⁴⁷⁶⁶⁷ is an apocalyptic number.

647667 is a deficient number, since it is larger than the sum of its proper divisors (287865).

647667 is a wasteful number, since it uses less digits than its factorization.

647667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71969 (or 71966 counting only the distinct ones).

The product of its digits is 42336, while the sum is 36.

The square root of 647667 is about 804.7776090325. Note that the first 3 decimals coincide. The cubic root of 647667 is about 86.5201485580.

The spelling of 647667 in words is "six hundred forty-seven thousand, six hundred sixty-seven".