123655680 has 160 divisors (see below), whose sum is σ = 439480800. Its totient is φ = 32956416.

The previous prime is 123655661. The next prime is 123655687. The reversal of 123655680 is 86556321.

123655680 is a `hidden beast` number, since 1 + 23 + 6 + 556 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123655687) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 68226 + ... + 70014.

It is an arithmetic number, because the mean of its divisors is an integer number (2746755).

Almost surely, 2^123655680 is an apocalyptic number.

123655680 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 123655680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (219740400).

123655680 is an abundant number, since it is smaller than the sum of its proper divisors (315825120).

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

123655680 is an equidigital number, since it uses as much as digits as its factorization.

123655680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1821 (or 1799 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 123655680 is about 11120.0575538079. The cubic root of 123655680 is about 498.2011090779.

The spelling of 123655680 in words is "one hundred twenty-three million, six hundred fifty-five thousand, six hundred eighty".