643554344381 has 8 divisors (see below), whose sum is σ = 699535708704. Its totient is φ = 588498292080.

The previous prime is 643554344369. The next prime is 643554344399. The reversal of 643554344381 is 183443455346.

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 643554344381 - 2¹⁰ = 643554343357 is a prime.

It is a super-2 number, since 2×643554344381² (a number of 24 digits) 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 (643554340381) 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, 231326555 + ... + 231329336.

It is an arithmetic number, because the mean of its divisors is an integer number (87441963588).

Almost surely, 2^643554344381 is an apocalyptic number.

It is an amenable number.

643554344381 is a deficient number, since it is larger than the sum of its proper divisors (55981364323).

643554344381 is a wasteful number, since it uses less digits than its factorization.

643554344381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462656011.

The product of its digits is 8294400, while the sum is 50.

The spelling of 643554344381 in words is "six hundred forty-three billion, five hundred fifty-four million, three hundred forty-four thousand, three hundred eighty-one".