3997689647 has 6 divisors (see below), whose sum is σ = 4650373728. Its totient is φ = 3426591084.

The previous prime is 3997689637. The next prime is 3997689649. The reversal of 3997689647 is 7469867993.

It is not a de Polignac number, because 3997689647 - 2⁸ = 3997689391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3997689649) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 40792703 + ... + 40792800.

It is an arithmetic number, because the mean of its divisors is an integer number (775062288).

Almost surely, 2^3997689647 is an apocalyptic number.

3997689647 is a deficient number, since it is larger than the sum of its proper divisors (652684081).

3997689647 is an equidigital number, since it uses as much as digits as its factorization.

3997689647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81585517 (or 81585510 counting only the distinct ones).

The product of its digits is 123451776, while the sum is 68.

The square root of 3997689647 is about 63227.2856210038. The cubic root of 3997689647 is about 1587.0953717097.

The spelling of 3997689647 in words is "three billion, nine hundred ninety-seven million, six hundred eighty-nine thousand, six hundred forty-seven".