728121000 has 128 divisors (see below), whose sum is σ = 2287209600. Its totient is φ = 192844800.

The previous prime is 728120977. The next prime is 728121001. The reversal of 728121000 is 121827.

It is not an unprimeable number, because it can be changed into a prime (728121001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 488256 + ... + 489744.

It is an arithmetic number, because the mean of its divisors is an integer number (17868825).

Almost surely, 2^728121000 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 728121000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1143604800).

728121000 is an abundant number, since it is smaller than the sum of its proper divisors (1559088600).

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

728121000 is a wasteful number, since it uses less digits than its factorization.

728121000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1676 (or 1662 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 728121000 is about 26983.7173124831. The cubic root of 728121000 is about 899.6381261214.

Adding to 728121000 its reverse (121827), we get a palindrome (728242827).

The spelling of 728121000 in words is "seven hundred twenty-eight million, one hundred twenty-one thousand".