122705728 has 56 divisors (see below), whose sum is σ = 266776200. Its totient is φ = 55738368.

The previous prime is 122705717. The next prime is 122705741. The reversal of 122705728 is 827507221.

It can be written as a sum of positive squares in 4 ways, for example, as 47224384 + 75481344 = 6872^2 + 8688^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 122705693 and 122705702.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29608 + ... + 33496.

Almost surely, 2^122705728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 122705728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133388100).

122705728 is an abundant number, since it is smaller than the sum of its proper divisors (144070472).

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

122705728 is a wasteful number, since it uses less digits than its factorization.

122705728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3947 (or 3937 counting only the distinct ones).

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 122705728 is about 11077.2617555062. The cubic root of 122705728 is about 496.9220621430.

The spelling of 122705728 in words is "one hundred twenty-two million, seven hundred five thousand, seven hundred twenty-eight".