643909279104 has 384 divisors, whose sum is σ = 2327071656000. Its totient is φ = 169820872704.

The previous prime is 643909279087. The next prime is 643909279141. The reversal of 643909279104 is 401972909346.

643909279104 is a `hidden beast` number, since 64 + 390 + 92 + 7 + 9 + 104 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5074092 + ... + 5199444.

Almost surely, 2^643909279104 is an apocalyptic number.

643909279104 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643909279104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1163535828000).

643909279104 is an abundant number, since it is smaller than the sum of its proper divisors (1683162376896).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643909279104 is a wasteful number, since it uses less digits than its factorization.

643909279104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125407 (or 125378 counting only the distinct ones).

The product of its (nonzero) digits is 2939328, while the sum is 54.

The spelling of 643909279104 in words is "six hundred forty-three billion, nine hundred nine million, two hundred seventy-nine thousand, one hundred four".