721098 has 48 divisors (see below), whose sum is σ = 1834560. Its totient is φ = 200448.

The previous prime is 721087. The next prime is 721109. The reversal of 721098 is 890127.

It is an interprime number because it is at equal distance from previous prime (721087) and next prime (721109).

It is an alternating number because its digits alternate between odd and even.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721098.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7386 + ... + 7482.

It is an arithmetic number, because the mean of its divisors is an integer number (38220).

2⁷²¹⁰⁹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721098, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (917280).

721098 is an abundant number, since it is smaller than the sum of its proper divisors (1113462).

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

721098 is a wasteful number, since it uses less digits than its factorization.

721098 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 721098 is about 849.1748936468. The cubic root of 721098 is about 89.6736327389.

The spelling of 721098 in words is "seven hundred twenty-one thousand, ninety-eight".