990010001081 has 2 divisors, whose sum is σ = 990010001082. Its totient is φ = 990010001080.

The previous prime is 990010001077. The next prime is 990010001107. The reversal of 990010001081 is 180100010099.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 576452970025 + 413557031056 = 759245^2 + 643084^2 .

It is a cyclic number.

It is not a de Polignac number, because 990010001081 - 2² = 990010001077 is a prime.

It is a super-2 number, since 2×990010001081² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (990010001381) 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, 495005000540 + 495005000541.

It is an arithmetic number, because the mean of its divisors is an integer number (495005000541).

Almost surely, 2^990010001081 is an apocalyptic number.

It is an amenable number.

990010001081 is a deficient number, since it is larger than the sum of its proper divisors (1).

990010001081 is an equidigital number, since it uses as much as digits as its factorization.

990010001081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 29.

The spelling of 990010001081 in words is "nine hundred ninety billion, ten million, one thousand, eighty-one".