123311540 has 48 divisors (see below), whose sum is σ = 299121984. Its totient is φ = 42201600.

The previous prime is 123311537. The next prime is 123311543. The reversal of 123311540 is 45113321.

It is an interprime number because it is at equal distance from previous prime (123311537) and next prime (123311543).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123311543) 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, 12746 + ... + 20225.

It is an arithmetic number, because the mean of its divisors is an integer number (6231708).

Almost surely, 2^123311540 is an apocalyptic number.

123311540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123311540 is an abundant number, since it is smaller than the sum of its proper divisors (175810444).

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

123311540 is a wasteful number, since it uses less digits than its factorization.

123311540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33008 (or 33006 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 123311540 is about 11104.5729319051. The cubic root of 123311540 is about 497.7385067177.

Adding to 123311540 its reverse (45113321), we get a palindrome (168424861).

The spelling of 123311540 in words is "one hundred twenty-three million, three hundred eleven thousand, five hundred forty".