647972211 has 4 divisors (see below), whose sum is σ = 863962952. Its totient is φ = 431981472.

The previous prime is 647972183. The next prime is 647972233. The reversal of 647972211 is 112279746.

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

It is not a de Polignac number, because 647972211 - 2⁵ = 647972179 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 647972211.

It is not an unprimeable number, because it can be changed into a prime (647972251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107995366 + ... + 107995371.

It is an arithmetic number, because the mean of its divisors is an integer number (215990738).

Almost surely, 2^647972211 is an apocalyptic number.

647972211 is a deficient number, since it is larger than the sum of its proper divisors (215990741).

647972211 is a wasteful number, since it uses less digits than its factorization.

647972211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215990740.

The product of its digits is 42336, while the sum is 39.

The square root of 647972211 is about 25455.2982893542. The cubic root of 647972211 is about 865.3373720467.

The spelling of 647972211 in words is "six hundred forty-seven million, nine hundred seventy-two thousand, two hundred eleven".