643169997 has 8 divisors (see below), whose sum is σ = 952844480. Its totient is φ = 428779980.

The previous prime is 643169983. The next prime is 643170013. The reversal of 643169997 is 799961346.

It is not a de Polignac number, because 643169997 - 2¹⁶ = 643104461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643169977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11910529 + ... + 11910582.

It is an arithmetic number, because the mean of its divisors is an integer number (119105560).

Almost surely, 2^643169997 is an apocalyptic number.

It is an amenable number.

643169997 is a deficient number, since it is larger than the sum of its proper divisors (309674483).

643169997 is a wasteful number, since it uses less digits than its factorization.

643169997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23821120 (or 23821114 counting only the distinct ones).

The product of its digits is 2204496, while the sum is 54.

The square root of 643169997 is about 25360.7964583134. The cubic root of 643169997 is about 863.1943565475.

The spelling of 643169997 in words is "six hundred forty-three million, one hundred sixty-nine thousand, nine hundred ninety-seven".