721734 has 32 divisors (see below), whose sum is σ = 1639680. Its totient is φ = 209952.

The previous prime is 721733. The next prime is 721739. The reversal of 721734 is 437127.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721733) 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, 1239 + ... + 1725.

It is an arithmetic number, because the mean of its divisors is an integer number (51240).

2⁷²¹⁷³⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721734, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (819840).

721734 is an abundant number, since it is smaller than the sum of its proper divisors (917946).

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

721734 is a wasteful number, since it uses less digits than its factorization.

721734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524.

The product of its digits is 1176, while the sum is 24.

The square root of 721734 is about 849.5492922721. The cubic root of 721734 is about 89.6999886902.

The spelling of 721734 in words is "seven hundred twenty-one thousand, seven hundred thirty-four".