990111001001 has 2 divisors, whose sum is σ = 990111001002. Its totient is φ = 990111001000.

The previous prime is 990111000997. The next prime is 990111001007. The reversal of 990111001001 is 100100111099.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 964471305625 + 25639695376 = 982075^2 + 160124^2 .

It is a cyclic number.

It is not a de Polignac number, because 990111001001 - 2² = 990111000997 is a prime.

It is not a weakly prime, because it can be changed into another prime (990111001007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495055500500 + 495055500501.

It is an arithmetic number, because the mean of its divisors is an integer number (495055500501).

Almost surely, 2^990111001001 is an apocalyptic number.

It is an amenable number.

990111001001 is a deficient number, since it is larger than the sum of its proper divisors (1).

990111001001 is an equidigital number, since it uses as much as digits as its factorization.

990111001001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81, while the sum is 23.

The spelling of 990111001001 in words is "nine hundred ninety billion, one hundred eleven million, one thousand, one".