123505978 has 4 divisors (see below), whose sum is σ = 185258970. Its totient is φ = 61752988.

The previous prime is 123505937. The next prime is 123505979. The reversal of 123505978 is 879505321.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 112635769 + 10870209 = 10613^2 + 3297^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 123505978.

It is not an unprimeable number, because it can be changed into a prime (123505979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30876493 + ... + 30876496.

Almost surely, 2^123505978 is an apocalyptic number.

123505978 is a deficient number, since it is larger than the sum of its proper divisors (61752992).

123505978 is an equidigital number, since it uses as much as digits as its factorization.

123505978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61752991.

The product of its (nonzero) digits is 75600, while the sum is 40.

The square root of 123505978 is about 11113.3243451273. The cubic root of 123505978 is about 497.9999811831. Note that the first 4 decimals are identical.

The spelling of 123505978 in words is "one hundred twenty-three million, five hundred five thousand, nine hundred seventy-eight".