643554455346 has 128 divisors (see below), whose sum is σ = 1602968555520. Its totient is φ = 189666360000.

The previous prime is 643554455333. The next prime is 643554455353.

643554455346 is a `hidden beast` number, since 6 + 4 + 3 + 5 + 5 + 44 + 553 + 46 = 666.

643554455346 is nontrivially palindromic in base 10.

643554455346 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 643554455292 and 643554455301.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 71445975 + ... + 71454981.

It is an arithmetic number, because the mean of its divisors is an integer number (12523191840).

Almost surely, 2^643554455346 is an apocalyptic number.

643554455346 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 643554455346, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (801484277760).

643554455346 is an abundant number, since it is smaller than the sum of its proper divisors (959414100174).

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

643554455346 is a wasteful number, since it uses less digits than its factorization.

643554455346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12317 (or 12311 counting only the distinct ones).

The product of its digits is 51840000, while the sum is 54.

The spelling of 643554455346 in words is "six hundred forty-three billion, five hundred fifty-four million, four hundred fifty-five thousand, three hundred forty-six".