123921980 has 144 divisors (see below), whose sum is σ = 333014976. Its totient is φ = 38384640.

The previous prime is 123921979. The next prime is 123921983. The reversal of 123921980 is 89129321.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 123921980.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123921983) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 904472 + ... + 904608.

It is an arithmetic number, because the mean of its divisors is an integer number (2312604).

Almost surely, 2^123921980 is an apocalyptic number.

123921980 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 123921980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (166507488).

123921980 is an abundant number, since it is smaller than the sum of its proper divisors (209092996).

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

123921980 is a wasteful number, since it uses less digits than its factorization.

123921980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 123921980 is about 11132.0249730227. The cubic root of 123921980 is about 498.5584880806.

The spelling of 123921980 in words is "one hundred twenty-three million, nine hundred twenty-one thousand, nine hundred eighty".