123455640 has 256 divisors, whose sum is σ = 477757440. Its totient is φ = 24768000.

The previous prime is 123455627. The next prime is 123455669. The reversal of 123455640 is 46554321.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 123455598 and 123455607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 286225 + ... + 286655.

It is an arithmetic number, because the mean of its divisors is an integer number (1866240).

Almost surely, 2^123455640 is an apocalyptic number.

123455640 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 123455640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (238878720).

123455640 is an abundant number, since it is smaller than the sum of its proper divisors (354301800).

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

123455640 is a wasteful number, since it uses less digits than its factorization.

123455640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 123455640 is about 11111.0593554350. The cubic root of 123455640 is about 497.9323144732.

The spelling of 123455640 in words is "one hundred twenty-three million, four hundred fifty-five thousand, six hundred forty".