648971997 has 16 divisors (see below), whose sum is σ = 875297280. Its totient is φ = 427663152.

The previous prime is 648971993. The next prime is 648972007. The reversal of 648971997 is 799179846.

It is not a de Polignac number, because 648971997 - 2² = 648971993 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 648971997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648971993) 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 15 ways as a sum of consecutive naturals, for example, 202038 + ... + 205224.

It is an arithmetic number, because the mean of its divisors is an integer number (54706080).

Almost surely, 2^648971997 is an apocalyptic number.

It is an amenable number.

648971997 is a deficient number, since it is larger than the sum of its proper divisors (226325283).

648971997 is a wasteful number, since it uses less digits than its factorization.

648971997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3952.

The product of its digits is 6858432, while the sum is 60.

The square root of 648971997 is about 25474.9287928347. The cubic root of 648971997 is about 865.7821995641.

The spelling of 648971997 in words is "six hundred forty-eight million, nine hundred seventy-one thousand, nine hundred ninety-seven".