123400254978 has 640 divisors, whose sum is σ = 395215349760. Its totient is φ = 27944611200.

The previous prime is 123400254937. The next prime is 123400255009. The reversal of 123400254978 is 879452004321.

123400254978 is a `hidden beast` number, since 1 + 2 + 34 + 0 + 0 + 2 + 549 + 78 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 372810273 + ... + 372810603.

It is an arithmetic number, because the mean of its divisors is an integer number (617523984).

Almost surely, 2^123400254978 is an apocalyptic number.

123400254978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 123400254978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (197607674880).

123400254978 is an abundant number, since it is smaller than the sum of its proper divisors (271815094782).

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

123400254978 is a wasteful number, since it uses less digits than its factorization.

123400254978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417 (or 386 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 123400254978 in words is "one hundred twenty-three billion, four hundred million, two hundred fifty-four thousand, nine hundred seventy-eight".