643934479 has 8 divisors (see below), whose sum is σ = 661102848. Its totient is φ = 626835840.

The previous prime is 643934477. The next prime is 643934497. The reversal of 643934479 is 974439346.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 643934479 - 2¹ = 643934477 is a prime.

It is a super-2 number, since 2×643934479² = 829303226490002882, 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 (643934477) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1554 + ... + 35920.

It is an arithmetic number, because the mean of its divisors is an integer number (82637856).

Almost surely, 2^643934479 is an apocalyptic number.

643934479 is a deficient number, since it is larger than the sum of its proper divisors (17168369).

643934479 is a wasteful number, since it uses less digits than its factorization.

643934479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34865.

The product of its digits is 1959552, while the sum is 49.

The square root of 643934479 is about 25375.8641035138. The cubic root of 643934479 is about 863.5362232749.

The spelling of 643934479 in words is "six hundred forty-three million, nine hundred thirty-four thousand, four hundred seventy-nine".