731497728 has 144 divisors (see below), whose sum is σ = 2148947136. Its totient is φ = 219463680.

The previous prime is 731497717. The next prime is 731497729. The reversal of 731497728 is 827794137.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (731497729) 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, 408451 + ... + 410237.

It is an arithmetic number, because the mean of its divisors is an integer number (14923244).

Almost surely, 2^731497728 is an apocalyptic number.

731497728 is a gapful number since it is divisible by the number (78) 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 731497728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1074473568).

731497728 is an abundant number, since it is smaller than the sum of its proper divisors (1417449408).

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

731497728 is a wasteful number, since it uses less digits than its factorization.

731497728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1860 (or 1846 counting only the distinct ones).

The product of its digits is 592704, while the sum is 48.

The square root of 731497728 is about 27046.2146704488. The cubic root of 731497728 is about 901.0266999232.

The spelling of 731497728 in words is "seven hundred thirty-one million, four hundred ninety-seven thousand, seven hundred twenty-eight".