643159971 has 12 divisors (see below), whose sum is σ = 969400848. Its totient is φ = 410130864.

The previous prime is 643159967. The next prime is 643159973. The reversal of 643159971 is 179951346.

It is not a de Polignac number, because 643159971 - 2² = 643159967 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643159973) 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 11 ways as a sum of consecutive naturals, for example, 1553320 + ... + 1553733.

It is an arithmetic number, because the mean of its divisors is an integer number (80783404).

Almost surely, 2^643159971 is an apocalyptic number.

643159971 is a deficient number, since it is larger than the sum of its proper divisors (326240877).

643159971 is a wasteful number, since it uses less digits than its factorization.

643159971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3107082 (or 3107079 counting only the distinct ones).

The product of its digits is 204120, while the sum is 45.

The square root of 643159971 is about 25360.5987902494. The cubic root of 643159971 is about 863.1898712473.

The spelling of 643159971 in words is "six hundred forty-three million, one hundred fifty-nine thousand, nine hundred seventy-one".