123556780 has 48 divisors (see below), whose sum is σ = 270908064. Its totient is φ = 47290880.

The previous prime is 123556751. The next prime is 123556813. The reversal of 123556780 is 87655321.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42039 + ... + 44881.

It is an arithmetic number, because the mean of its divisors is an integer number (5643918).

Almost surely, 2^123556780 is an apocalyptic number.

123556780 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 123556780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135454032).

123556780 is an abundant number, since it is smaller than the sum of its proper divisors (147351284).

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

123556780 is a wasteful number, since it uses less digits than its factorization.

123556780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2946 (or 2944 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 37.

The square root of 123556780 is about 11115.6097448588. The cubic root of 123556780 is about 498.0682529851.

The spelling of 123556780 in words is "one hundred twenty-three million, five hundred fifty-six thousand, seven hundred eighty".