990011205505531 has 4 divisors (see below), whose sum is σ = 1080012224187864. Its totient is φ = 900010186823200.

The previous prime is 990011205505477. The next prime is 990011205505571. The reversal of 990011205505531 is 135505502110099.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990011205505531 is a prime.

It is a super-2 number, since 2×990011205505531² (a number of 31 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (990011205505571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45000509341150 + ... + 45000509341171.

It is an arithmetic number, because the mean of its divisors is an integer number (270003056046966).

Almost surely, 2^{990011205505531} is an apocalyptic number.

990011205505531 is a deficient number, since it is larger than the sum of its proper divisors (90001018682333).

990011205505531 is a wasteful number, since it uses less digits than its factorization.

990011205505531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90001018682332.

The product of its (nonzero) digits is 303750, while the sum is 46.

The spelling of 990011205505531 in words is "nine hundred ninety trillion, eleven billion, two hundred five million, five hundred five thousand, five hundred thirty-one".