1001311021 has 2 divisors, whose sum is σ = 1001311022. Its totient is φ = 1001311020.

The previous prime is 1001311013. The next prime is 1001311081. The reversal of 1001311021 is 1201131001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 570540996 + 430770025 = 23886^2 + 20755^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001311021 - 2³ = 1001311013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1001310989 and 1001311007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001311081) 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, 500655510 + 500655511.

It is an arithmetic number, because the mean of its divisors is an integer number (500655511).

Almost surely, 2^1001311021 is an apocalyptic number.

It is an amenable number.

1001311021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001311021 is an equidigital number, since it uses as much as digits as its factorization.

1001311021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6, while the sum is 10.

The square root of 1001311021 is about 31643.4988741764. The cubic root of 1001311021 is about 1000.4368161639.

Adding to 1001311021 its reverse (1201131001), we get a palindrome (2202442022).

The spelling of 1001311021 in words is "one billion, one million, three hundred eleven thousand, twenty-one".