647977471 has 4 divisors (see below), whose sum is σ = 658960200. Its totient is φ = 636994744.

The previous prime is 647977439. The next prime is 647977507. The reversal of 647977471 is 174779746.

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 647977471 - 2⁵ = 647977439 is a prime.

It is a super-3 number, since 3×647977471³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647977271) 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, 5491276 + ... + 5491393.

It is an arithmetic number, because the mean of its divisors is an integer number (164740050).

Almost surely, 2^647977471 is an apocalyptic number.

647977471 is a deficient number, since it is larger than the sum of its proper divisors (10982729).

647977471 is a wasteful number, since it uses less digits than its factorization.

647977471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10982728.

The product of its digits is 2074464, while the sum is 52.

The square root of 647977471 is about 25455.4016075174. The cubic root of 647977471 is about 865.3397135372.

The spelling of 647977471 in words is "six hundred forty-seven million, nine hundred seventy-seven thousand, four hundred seventy-one".