123551781534720 has 1584 divisors, whose sum is σ = 545551415282016. Its totient is φ = 25565331456000.

The previous prime is 123551781534697. The next prime is 123551781534773. The reversal of 123551781534720 is 27435187155321.

123551781534720 is a `hidden beast` number, since 1 + 2 + 3 + 5 + 5 + 1 + 7 + 81 + 534 + 7 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (1584).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 5985735600 + ... + 5985756240.

It is an arithmetic number, because the mean of its divisors is an integer number (344413772274).

Almost surely, 2^{123551781534720} is an apocalyptic number.

123551781534720 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 123551781534720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (272775707641008).

123551781534720 is an abundant number, since it is smaller than the sum of its proper divisors (421999633747296).

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

123551781534720 is a wasteful number, since it uses less digits than its factorization.

123551781534720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20938 (or 20910 counting only the distinct ones).

The product of its (nonzero) digits is 7056000, while the sum is 54.

The spelling of 123551781534720 in words is "one hundred twenty-three trillion, five hundred fifty-one billion, seven hundred eighty-one million, five hundred thirty-four thousand, seven hundred twenty".