1005721331 has 2 divisors, whose sum is σ = 1005721332. Its totient is φ = 1005721330.

The previous prime is 1005721307. The next prime is 1005721361. The reversal of 1005721331 is 1331275001.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1005721331 is a prime.

It is a super-2 number, since 2×1005721331² = 2022950791256823122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1005721297 and 1005721306.

It is not a weakly prime, because it can be changed into another prime (1005721361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502860665 + 502860666.

It is an arithmetic number, because the mean of its divisors is an integer number (502860666).

Almost surely, 2^1005721331 is an apocalyptic number.

1005721331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1005721331 is an equidigital number, since it uses as much as digits as its factorization.

1005721331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 630, while the sum is 23.

The square root of 1005721331 is about 31713.1097655213. The cubic root of 1005721331 is about 1001.9034847801.

Adding to 1005721331 its reverse (1331275001), we get a palindrome (2336996332).

The spelling of 1005721331 in words is "one billion, five million, seven hundred twenty-one thousand, three hundred thirty-one".