647123 has 4 divisors (see below), whose sum is σ = 648768. Its totient is φ = 645480.

The previous prime is 647117. The next prime is 647131. The reversal of 647123 is 321746.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 647123 - 2¹⁰ = 646099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158 + ... + 1148.

It is an arithmetic number, because the mean of its divisors is an integer number (162192).

2⁶⁴⁷¹²³ is an apocalyptic number.

647123 is a deficient number, since it is larger than the sum of its proper divisors (1645).

647123 is an equidigital number, since it uses as much as digits as its factorization.

647123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1644.

The product of its digits is 1008, while the sum is 23.

The square root of 647123 is about 804.4395564615. The cubic root of 647123 is about 86.4959179247.

Adding to 647123 its reverse (321746), we get a palindrome (968869).

The spelling of 647123 in words is "six hundred forty-seven thousand, one hundred twenty-three".