61129728 has 220 divisors, whose sum is σ = 202112592. Its totient is φ = 18247680.

The previous prime is 61129721. The next prime is 61129759. The reversal of 61129728 is 82792116.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 61129692 and 61129701.

It is not an unprimeable number, because it can be changed into a prime (61129721) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 912351 + ... + 912417.

Almost surely, 2^61129728 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 61129728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101056296).

61129728 is an abundant number, since it is smaller than the sum of its proper divisors (140982864).

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

61129728 is a wasteful number, since it uses less digits than its factorization.

61129728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110 (or 83 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 61129728 is about 7818.5502492470. The cubic root of 61129728 is about 393.9285775009.

The spelling of 61129728 in words is "sixty-one million, one hundred twenty-nine thousand, seven hundred twenty-eight".