647641247 has 18 divisors (see below), whose sum is σ = 727638744. Its totient is φ = 576000040.

The previous prime is 647641223. The next prime is 647641249. The reversal of 647641247 is 742146746.

It is not a de Polignac number, because 647641247 - 2⁸ = 647640991 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 (647641249) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 266078 + ... + 268500.

Almost surely, 2^647641247 is an apocalyptic number.

647641247 is a deficient number, since it is larger than the sum of its proper divisors (79997497).

647641247 is a wasteful number, since it uses less digits than its factorization.

647641247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2539 (or 2481 counting only the distinct ones).

The product of its digits is 225792, while the sum is 41.

The square root of 647641247 is about 25448.7965727262. The cubic root of 647641247 is about 865.1900178405.

The spelling of 647641247 in words is "six hundred forty-seven million, six hundred forty-one thousand, two hundred forty-seven".