990007090081 has 3 divisors (see below), whose sum is σ = 990008085073. Its totient is φ = 990006095090.

The previous prime is 990007090069. The next prime is 990007090087. The reversal of 990007090081 is 180090700099.

The square root of 990007090081 is 994991.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 990007090081 - 2¹¹ = 990007088033 is a prime.

It is a super-2 number, since 2×990007090081² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (990007090087) 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 in 2 ways as a sum of consecutive naturals, for example, 497496 + ... + 1492486.

Almost surely, 2^990007090081 is an apocalyptic number.

990007090081 is the 994991-st square number.

990007090081 is the 497496-th centered octagonal number.

It is an amenable number.

990007090081 is a deficient number, since it is larger than the sum of its proper divisors (994992).

990007090081 is an frugal number, since it uses more digits than its factorization.

990007090081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1989982 (or 994991 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 43.

The spelling of 990007090081 in words is "nine hundred ninety billion, seven million, ninety thousand, eighty-one".