647986197 has 4 divisors (see below), whose sum is σ = 863981600. Its totient is φ = 431990796.

The previous prime is 647986193. The next prime is 647986243. The reversal of 647986197 is 791689746.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 647986197 - 2² = 647986193 is a prime.

It is a super-2 number, since 2×647986197² = 839772223005045618, which contains 22 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 (647986193) 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, 107997697 + ... + 107997702.

It is an arithmetic number, because the mean of its divisors is an integer number (215995400).

Almost surely, 2^647986197 is an apocalyptic number.

It is an amenable number.

647986197 is a deficient number, since it is larger than the sum of its proper divisors (215995403).

647986197 is a wasteful number, since it uses less digits than its factorization.

647986197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215995402.

The product of its digits is 4572288, while the sum is 57.

The square root of 647986197 is about 25455.5730047469. The cubic root of 647986197 is about 865.3435978906.

The spelling of 647986197 in words is "six hundred forty-seven million, nine hundred eighty-six thousand, one hundred ninety-seven".