724221131 has 4 divisors (see below), whose sum is σ = 766822392. Its totient is φ = 681619872.

The previous prime is 724221037. The next prime is 724221133. The reversal of 724221131 is 131122427.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-724221131 is a prime.

It is a super-2 number, since 2×724221131² = 1048992493173838322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 724221097 and 724221106.

It is not an unprimeable number, because it can be changed into a prime (724221133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21300605 + ... + 21300638.

It is an arithmetic number, because the mean of its divisors is an integer number (191705598).

Almost surely, 2^724221131 is an apocalyptic number.

724221131 is a deficient number, since it is larger than the sum of its proper divisors (42601261).

724221131 is a wasteful number, since it uses less digits than its factorization.

724221131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42601260.

The product of its digits is 672, while the sum is 23.

The square root of 724221131 is about 26911.3569148789. The cubic root of 724221131 is about 898.0290742286.

Adding to 724221131 its reverse (131122427), we get a palindrome (855343558).

The spelling of 724221131 in words is "seven hundred twenty-four million, two hundred twenty-one thousand, one hundred thirty-one".