728297640 has 384 divisors, whose sum is σ = 2842594560. Its totient is φ = 158257152.

The previous prime is 728297639. The next prime is 728297657. The reversal of 728297640 is 46792827.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6806467 + ... + 6806573.

It is an arithmetic number, because the mean of its divisors is an integer number (7402590).

Almost surely, 2^728297640 is an apocalyptic number.

728297640 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 728297640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1421297280).

728297640 is an abundant number, since it is smaller than the sum of its proper divisors (2114296920).

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

728297640 is a wasteful number, since it uses less digits than its factorization.

728297640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 728297640 is about 26986.9901989829. The cubic root of 728297640 is about 899.7108700883.

The spelling of 728297640 in words is "seven hundred twenty-eight million, two hundred ninety-seven thousand, six hundred forty".