728234640 has 480 divisors, whose sum is σ = 2971238400. Its totient is φ = 156349440.

The previous prime is 728234623. The next prime is 728234657. The reversal of 728234640 is 46432827.

728234640 is a `hidden beast` number, since 7 + 2 + 8 + 2 + 3 + 4 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (728234623) and next prime (728234657).

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 = 728234595 and 728234604.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9218121 + ... + 9218199.

It is an arithmetic number, because the mean of its divisors is an integer number (6190080).

Almost surely, 2^728234640 is an apocalyptic number.

728234640 is a gapful number since it is divisible by the number (70) 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 728234640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1485619200).

728234640 is an abundant number, since it is smaller than the sum of its proper divisors (2243003760).

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

728234640 is a wasteful number, since it uses less digits than its factorization.

728234640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 186 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 36.

The square root of 728234640 is about 26985.8229446500. The cubic root of 728234640 is about 899.6849267486.

The spelling of 728234640 in words is "seven hundred twenty-eight million, two hundred thirty-four thousand, six hundred forty".