724640 has 48 divisors (see below), whose sum is σ = 1959552. Its totient is φ = 248064.

The previous prime is 724639. The next prime is 724643. The reversal of 724640 is 46427.

It is not an unprimeable number, because it can be changed into a prime (724643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 797 + ... + 1443.

It is an arithmetic number, because the mean of its divisors is an integer number (40824).

2⁷²⁴⁶⁴⁰ is an apocalyptic number.

724640 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 724640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (979776).

724640 is an abundant number, since it is smaller than the sum of its proper divisors (1234912).

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

724640 is a wasteful number, since it uses less digits than its factorization.

724640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669 (or 661 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 724640 is about 851.2578927681. The cubic root of 724640 is about 89.8202172393.

The spelling of 724640 in words is "seven hundred twenty-four thousand, six hundred forty".