647642623 has 4 divisors (see below), whose sum is σ = 648103680. Its totient is φ = 647181568.

The previous prime is 647642549. The next prime is 647642629. The reversal of 647642623 is 326246746.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647642623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647642629) 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, 228415 + ... + 231232.

It is an arithmetic number, because the mean of its divisors is an integer number (162025920).

Almost surely, 2^647642623 is an apocalyptic number.

647642623 is a deficient number, since it is larger than the sum of its proper divisors (461057).

647642623 is a wasteful number, since it uses less digits than its factorization.

647642623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461056.

The product of its digits is 290304, while the sum is 40.

The square root of 647642623 is about 25448.8236073890. The cubic root of 647642623 is about 865.1906305771.

The spelling of 647642623 in words is "six hundred forty-seven million, six hundred forty-two thousand, six hundred twenty-three".