721118 has 8 divisors (see below), whose sum is σ = 1102248. Its totient is φ = 353704.

The previous prime is 721117. The next prime is 721129. The reversal of 721118 is 811127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×721118² = 1040022339848, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 721118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3296 + ... + 3507.

It is an arithmetic number, because the mean of its divisors is an integer number (137781).

2⁷²¹¹¹⁸ is an apocalyptic number.

721118 is a deficient number, since it is larger than the sum of its proper divisors (381130).

721118 is a wasteful number, since it uses less digits than its factorization.

721118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6858.

The product of its digits is 112, while the sum is 20.

The square root of 721118 is about 849.1866697023. The cubic root of 721118 is about 89.6744617783.

Subtracting 721118 from its reverse (811127), we obtain a palindrome (90009).

It can be divided in two parts, 721 and 118, that multiplied together give a triangular number (85078 = T₄₁₂).

The spelling of 721118 in words is "seven hundred twenty-one thousand, one hundred eighteen".