123115405540 has 48 divisors (see below), whose sum is σ = 263671193520. Its totient is φ = 48271009280.

The previous prime is 123115405513. The next prime is 123115405559. The reversal of 123115405540 is 45504511321.

It can be written as a sum of positive squares in 8 ways, for example, as 12799754496 + 110315651044 = 113136^2 + 332138^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1069926 + ... + 1179394.

It is an arithmetic number, because the mean of its divisors is an integer number (5493149865).

Almost surely, 2^123115405540 is an apocalyptic number.

123115405540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123115405540 is an abundant number, since it is smaller than the sum of its proper divisors (140555787980).

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

123115405540 is a wasteful number, since it uses less digits than its factorization.

123115405540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110592 (or 110590 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 31.

Adding to 123115405540 its reverse (45504511321), we get a palindrome (168619916861).

The spelling of 123115405540 in words is "one hundred twenty-three billion, one hundred fifteen million, four hundred five thousand, five hundred forty".