643321829831361 has 32 divisors (see below), whose sum is σ = 863209169827200. Its totient is φ = 426166767552000.

The previous prime is 643321829831347. The next prime is 643321829831381. The reversal of 643321829831361 is 163138928123346.

It is a de Polignac number, because none of the positive numbers 2^k-643321829831361 is a prime.

It is a super-2 number, since 2×643321829831361² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643321829831295 and 643321829831304.

It is not an unprimeable number, because it can be changed into a prime (643321829831341) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 749915485 + ... + 750772853.

It is an arithmetic number, because the mean of its divisors is an integer number (26975286557100).

Almost surely, 2^{643321829831361} is an apocalyptic number.

It is an amenable number.

643321829831361 is a deficient number, since it is larger than the sum of its proper divisors (219887339995839).

643321829831361 is a wasteful number, since it uses less digits than its factorization.

643321829831361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 859969.

The product of its digits is 26873856, while the sum is 60.

The spelling of 643321829831361 in words is "six hundred forty-three trillion, three hundred twenty-one billion, eight hundred twenty-nine million, eight hundred thirty-one thousand, three hundred sixty-one".