123240440 has 64 divisors (see below), whose sum is σ = 292541760. Its totient is φ = 46632960.

The previous prime is 123240437. The next prime is 123240449. The reversal of 123240440 is 44042321.

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 (123240449) 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, 88550 + ... + 89930.

It is an arithmetic number, because the mean of its divisors is an integer number (4570965).

Almost surely, 2^123240440 is an apocalyptic number.

123240440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 123240440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146270880).

123240440 is an abundant number, since it is smaller than the sum of its proper divisors (169301320).

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

123240440 is a wasteful number, since it uses less digits than its factorization.

123240440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1512 (or 1508 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 123240440 is about 11101.3710864920. The cubic root of 123240440 is about 497.6428249140.

Adding to 123240440 its reverse (44042321), we get a palindrome (167282761).

The spelling of 123240440 in words is "one hundred twenty-three million, two hundred forty thousand, four hundred forty".