123555440 has 40 divisors (see below), whose sum is σ = 292146480. Its totient is φ = 48582656.

The previous prime is 123555413. The next prime is 123555449. The reversal of 123555440 is 44555321.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123555449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8369 + ... + 17808.

It is an arithmetic number, because the mean of its divisors is an integer number (7303662).

Almost surely, 2^123555440 is an apocalyptic number.

123555440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123555440 is an abundant number, since it is smaller than the sum of its proper divisors (168591040).

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

123555440 is a wasteful number, since it uses less digits than its factorization.

123555440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26249 (or 26243 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 29.

The square root of 123555440 is about 11115.5494690996. The cubic root of 123555440 is about 498.0664524259.

The spelling of 123555440 in words is "one hundred twenty-three million, five hundred fifty-five thousand, four hundred forty".