728720321890 has 32 divisors (see below), whose sum is σ = 1464219446976. Its totient is φ = 258826666560.

The previous prime is 728720321827. The next prime is 728720321891. The reversal of 728720321890 is 98123027827.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (728720321891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77027017 + ... + 77036476.

It is an arithmetic number, because the mean of its divisors is an integer number (45756857718).

Almost surely, 2^728720321890 is an apocalyptic number.

728720321890 is an abundant number, since it is smaller than the sum of its proper divisors (735499125086).

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

728720321890 is a wasteful number, since it uses less digits than its factorization.

728720321890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154063554.

The product of its (nonzero) digits is 677376, while the sum is 49.

The spelling of 728720321890 in words is "seven hundred twenty-eight billion, seven hundred twenty million, three hundred twenty-one thousand, eight hundred ninety".