1001022991 has 2 divisors, whose sum is σ = 1001022992. Its totient is φ = 1001022990.

The previous prime is 1001022989. The next prime is 1001023003. The reversal of 1001022991 is 1992201001.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1001022991 - 2¹ = 1001022989 is a prime.

Together with 1001022989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001022931) 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 as a sum of consecutive naturals, namely, 500511495 + 500511496.

It is an arithmetic number, because the mean of its divisors is an integer number (500511496).

Almost surely, 2^1001022991 is an apocalyptic number.

1001022991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001022991 is an equidigital number, since it uses as much as digits as its factorization.

1001022991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 1001022991 is about 31638.9473750313. The cubic root of 1001022991 is about 1000.3408807871.

Adding to 1001022991 its reverse (1992201001), we get a palindrome (2993223992).

The spelling of 1001022991 in words is "one billion, one million, twenty-two thousand, nine hundred ninety-one".