643091071 has 8 divisors (see below), whose sum is σ = 735740064. Its totient is φ = 550636800.

The previous prime is 643091069. The next prime is 643091077. The reversal of 643091071 is 170190346.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 643091071 - 2¹ = 643091069 is a prime.

It is a super-2 number, since 2×643091071² = 827132251199854082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643091077) 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 7 ways as a sum of consecutive naturals, for example, 41530 + ... + 54871.

It is an arithmetic number, because the mean of its divisors is an integer number (91967508).

Almost surely, 2^643091071 is an apocalyptic number.

643091071 is a deficient number, since it is larger than the sum of its proper divisors (92648993).

643091071 is an equidigital number, since it uses as much as digits as its factorization.

643091071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97361.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 643091071 is about 25359.2403474552. The cubic root of 643091071 is about 863.1590464091.

The spelling of 643091071 in words is "six hundred forty-three million, ninety-one thousand, seventy-one".