61131728 has 80 divisors (see below), whose sum is σ = 145240704. Its totient is φ = 24330240.

The previous prime is 61131727. The next prime is 61131751. The reversal of 61131728 is 82713116.

61131728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 61131728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61131727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 184523 + ... + 184853.

Almost surely, 2^61131728 is an apocalyptic number.

61131728 is a gapful number since it is divisible by the number (68) 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 61131728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72620352).

61131728 is an abundant number, since it is smaller than the sum of its proper divisors (84108976).

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

61131728 is a wasteful number, since it uses less digits than its factorization.

61131728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 460 (or 454 counting only the distinct ones).

The product of its digits is 2016, while the sum is 29.

The square root of 61131728 is about 7818.6781491503. The cubic root of 61131728 is about 393.9328735479.

The spelling of 61131728 in words is "sixty-one million, one hundred thirty-one thousand, seven hundred twenty-eight".