123780 has 24 divisors (see below), whose sum is σ = 346752. Its totient is φ = 32992.

The previous prime is 123757. The next prime is 123787. The reversal of 123780 is 87321.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (123787) by changing a digit.

123780 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 972 + ... + 1091.

It is an arithmetic number, because the mean of its divisors is an integer number (14448).

2¹²³⁷⁸⁰ is an apocalyptic number.

123780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123780 is an abundant number, since it is smaller than the sum of its proper divisors (222972).

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

123780 is a wasteful number, since it uses less digits than its factorization.

123780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2075 (or 2073 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 123780 is about 351.8238195461. The cubic root of 123780 is about 49.8368012362.

It can be divided in two parts, 123 and 780, that added together give a triangular number (903 = T₄₂).

The spelling of 123780 in words is "one hundred twenty-three thousand, seven hundred eighty".