1990101001001 has 2 divisors, whose sum is σ = 1990101001002. Its totient is φ = 1990101001000.

The previous prime is 1990101000949. The next prime is 1990101001033. The reversal of 1990101001001 is 1001001010991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1887972181225 + 102128819776 = 1374035^2 + 319576^2 .

It is an emirp because it is prime and its reverse (1001001010991) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1990101001001 is a prime.

It is not a weakly prime, because it can be changed into another prime (1990101031001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995050500500 + 995050500501.

It is an arithmetic number, because the mean of its divisors is an integer number (995050500501).

Almost surely, 2^{1990101001001} is an apocalyptic number.

It is an amenable number.

1990101001001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990101001001 is an equidigital number, since it uses as much as digits as its factorization.

1990101001001 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.

Adding to 1990101001001 its reverse (1001001010991), we get a palindrome (2991102011992).

The spelling of 1990101001001 in words is "one trillion, nine hundred ninety billion, one hundred one million, one thousand, one".