123544243021 has 16 divisors (see below), whose sum is σ = 136569888000. Its totient is φ = 111163664128.

The previous prime is 123544242973. The next prime is 123544243063. The reversal of 123544243021 is 120342445321.

It is a cyclic number.

It is not a de Polignac number, because 123544243021 - 2¹⁷ = 123544111949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123544243091) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 681000 + ... + 843118.

It is an arithmetic number, because the mean of its divisors is an integer number (8535618000).

Almost surely, 2^123544243021 is an apocalyptic number.

It is an amenable number.

123544243021 is a deficient number, since it is larger than the sum of its proper divisors (13025644979).

123544243021 is a wasteful number, since it uses less digits than its factorization.

123544243021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164108.

The product of its (nonzero) digits is 23040, while the sum is 31.

Adding to 123544243021 its reverse (120342445321), we get a palindrome (243886688342).

The spelling of 123544243021 in words is "one hundred twenty-three billion, five hundred forty-four million, two hundred forty-three thousand, twenty-one".