648731997 has 40 divisors (see below), whose sum is σ = 1016097984. Its totient is φ = 413395488.

The previous prime is 648731977. The next prime is 648732037. The reversal of 648731997 is 799137846.

It is a happy number.

It is not a de Polignac number, because 648731997 - 2²⁸ = 380296541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648731957) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 451993 + ... + 453425.

Almost surely, 2^648731997 is an apocalyptic number.

It is an amenable number.

648731997 is a deficient number, since it is larger than the sum of its proper divisors (367365987).

648731997 is an frugal number, since it uses more digits than its factorization.

648731997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1483 (or 1459 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 54.

The square root of 648731997 is about 25470.2178435914. The cubic root of 648731997 is about 865.6754598031.

The spelling of 648731997 in words is "six hundred forty-eight million, seven hundred thirty-one thousand, nine hundred ninety-seven".