643161721122 has 54 divisors (see below), whose sum is σ = 1447247071569. Its totient is φ = 214356618000.

The previous prime is 643161721087. The next prime is 643161721219. The reversal of 643161721122 is 221127161346.

643161721122 is a `hidden beast` number, since 6 + 4 + 3 + 1 + 617 + 2 + 11 + 22 = 666.

643161721122 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 639281801601 + 3879919521 = 799551^2 + 62289^2 .

It is a tau number, because it is divible by the number of its divisors (54).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=567081.

It is a super-2 number, since 2×643161721122² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 91863622 + ... + 91870622.

Almost surely, 2^643161721122 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643161721122

643161721122 is an abundant number, since it is smaller than the sum of its proper divisors (804085350447).

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

643161721122 is an frugal number, since it uses more digits than its factorization.

643161721122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14028 (or 7006 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

Adding to 643161721122 its reverse (221127161346), we get a palindrome (864288882468).

The spelling of 643161721122 in words is "six hundred forty-three billion, one hundred sixty-one million, seven hundred twenty-one thousand, one hundred twenty-two".