123311440 has 120 divisors (see below), whose sum is σ = 338415840. Its totient is φ = 41658624.

The previous prime is 123311431. The next prime is 123311467. The reversal of 123311440 is 44113321.

It is a super-2 number, since 2×123311440² = 30411422469747200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 325171 + ... + 325549.

It is an arithmetic number, because the mean of its divisors is an integer number (2820132).

Almost surely, 2^123311440 is an apocalyptic number.

123311440 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 123311440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169207920).

123311440 is an abundant number, since it is smaller than the sum of its proper divisors (215104400).

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

123311440 is a wasteful number, since it uses less digits than its factorization.

123311440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489 (or 476 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 123311440 is about 11104.5684292547. The cubic root of 123311440 is about 497.7383721700.

Adding to 123311440 its reverse (44113321), we get a palindrome (167424761).

The spelling of 123311440 in words is "one hundred twenty-three million, three hundred eleven thousand, four hundred forty".