123551340 has 96 divisors (see below), whose sum is σ = 380540160. Its totient is φ = 29702400.

The previous prime is 123551317. The next prime is 123551353. The reversal of 123551340 is 43155321.

123551340 is a nontrivial binomial coefficient, being equal to C(15720, 2).

It is a self number, because there is not a number n which added to its sum of digits gives 123551340.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85746 + ... + 87174.

It is an arithmetic number, because the mean of its divisors is an integer number (3963960).

Almost surely, 2^123551340 is an apocalyptic number.

123551340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

123551340 is the 15719-th triangular number and also the 7860-th hexagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 123551340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (190270080).

123551340 is an abundant number, since it is smaller than the sum of its proper divisors (256988820).

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

123551340 is a wasteful number, since it uses less digits than its factorization.

123551340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1583 (or 1581 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 123551340 is about 11115.3650412391. The cubic root of 123551340 is about 498.0609431716.

It can be divided in two parts, 12355 and 1340, that added together give a triangular number (13695 = T₁₆₅).

The spelling of 123551340 in words is "one hundred twenty-three million, five hundred fifty-one thousand, three hundred forty".