721131 has 8 divisors (see below), whose sum is σ = 966144. Its totient is φ = 478440.

The previous prime is 721129. The next prime is 721139. The reversal of 721131 is 131127.

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

It is not a de Polignac number, because 721131 - 2¹ = 721129 is a prime.

It is a super-2 number, since 2×721131² = 1040059838322, 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 721131.

It is not an unprimeable number, because it can be changed into a prime (721139) 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, 370 + ... + 1256.

It is an arithmetic number, because the mean of its divisors is an integer number (120768).

2⁷²¹¹³¹ is an apocalyptic number.

721131 is a deficient number, since it is larger than the sum of its proper divisors (245013).

721131 is a wasteful number, since it uses less digits than its factorization.

721131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1161.

The product of its digits is 42, while the sum is 15.

The square root of 721131 is about 849.1943240507. The cubic root of 721131 is about 89.6750006457.

Adding to 721131 its reverse (131127), we get a palindrome (852258).

The spelling of 721131 in words is "seven hundred twenty-one thousand, one hundred thirty-one".