647423999 has 4 divisors (see below), whose sum is σ = 649466664. Its totient is φ = 645381336.

The previous prime is 647423977. The next prime is 647424007. The reversal of 647423999 is 999324746.

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

It is a cyclic number.

It is not a de Polignac number, because 647423999 - 2¹⁶ = 647358463 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 647423999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647423969) 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, 1020857 + ... + 1021490.

It is an arithmetic number, because the mean of its divisors is an integer number (162366666).

Almost surely, 2^647423999 is an apocalyptic number.

647423999 is a deficient number, since it is larger than the sum of its proper divisors (2042665).

647423999 is a wasteful number, since it uses less digits than its factorization.

647423999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2042664.

The product of its digits is 2939328, while the sum is 53.

The square root of 647423999 is about 25444.5278792907. The cubic root of 647423999 is about 865.0932658075.

The spelling of 647423999 in words is "six hundred forty-seven million, four hundred twenty-three thousand, nine hundred ninety-nine".