721093 has 4 divisors (see below), whose sum is σ = 740620. Its totient is φ = 701568.

The previous prime is 721087. The next prime is 721109. The reversal of 721093 is 390127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 390127 = 19 ⋅20533.

It can be written as a sum of positive squares in 2 ways, for example, as 289444 + 431649 = 538^2 + 657^2 .

It is a cyclic number.

It is not a de Polignac number, because 721093 - 2¹⁷ = 590021 is a prime.

It is a super-2 number, since 2×721093² = 1039950229298, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721003) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 9708 + ... + 9781.

It is an arithmetic number, because the mean of its divisors is an integer number (185155).

2⁷²¹⁰⁹³ is an apocalyptic number.

It is an amenable number.

721093 is a deficient number, since it is larger than the sum of its proper divisors (19527).

721093 is a wasteful number, since it uses less digits than its factorization.

721093 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19526.

The product of its (nonzero) digits is 378, while the sum is 22.

The square root of 721093 is about 849.1719496074. The cubic root of 721093 is about 89.6734254766.

The spelling of 721093 in words is "seven hundred twenty-one thousand, ninety-three".