990111111110001 has 20 divisors (see below), whose sum is σ = 1530056761744500. Its totient is φ = 637312899103776.

The previous prime is 990111111109949. The next prime is 990111111110027. The reversal of 990111111110001 is 100011111111099.

It can be written as a sum of positive squares in 2 ways, for example, as 672658459635600 + 317452651474401 = 25935660^2 + 17817201^2 .

It is not a de Polignac number, because 990111111110001 - 2⁷ = 990111111109873 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (990111111114001) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 210751617726 + ... + 210751622423.

It is an arithmetic number, because the mean of its divisors is an integer number (76502838087225).

Almost surely, 2^{990111111110001} is an apocalyptic number.

It is an amenable number.

990111111110001 is a deficient number, since it is larger than the sum of its proper divisors (539945650634499).

990111111110001 is a wasteful number, since it uses less digits than its factorization.

990111111110001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421503240190 (or 421503240181 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 27.

The spelling of 990111111110001 in words is "nine hundred ninety trillion, one hundred eleven billion, one hundred eleven million, one hundred ten thousand, one".