647720471381688 has 144 divisors (see below), whose sum is σ = 1908059856791400. Its totient is φ = 197945135164800.

The previous prime is 647720471381671. The next prime is 647720471381791. The reversal of 647720471381688 is 886183174027746.

647720471381688 is a `hidden beast` number, since 6 + 4 + 7 + 72 + 0 + 471 + 3 + 8 + 1 + 6 + 88 = 666.

It is a super-3 number, since 3×647720471381688³ (a number of 45 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 245032843 + ... + 247662138.

Almost surely, 2^{647720471381688} is an apocalyptic number.

It is an amenable number.

647720471381688 is an abundant number, since it is smaller than the sum of its proper divisors (1260339385409712).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

647720471381688 is a wasteful number, since it uses less digits than its factorization.

647720471381688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492695074 (or 492695036 counting only the distinct ones).

The product of its (nonzero) digits is 606928896, while the sum is 72.

The spelling of 647720471381688 in words is "six hundred forty-seven trillion, seven hundred twenty billion, four hundred seventy-one million, three hundred eighty-one thousand, six hundred eighty-eight".