990918991818 has 48 divisors (see below), whose sum is σ = 2513550626496. Its totient is φ = 276214351680.

The previous prime is 990918991787. The next prime is 990918991819. The reversal of 990918991818 is 818199819099.

It is not an unprimeable number, because it can be changed into a prime (990918991819) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 95902596 + ... + 95912927.

It is an arithmetic number, because the mean of its divisors is an integer number (52365638052).

Almost surely, 2^990918991818 is an apocalyptic number.

990918991818 is an abundant number, since it is smaller than the sum of its proper divisors (1522631634678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

990918991818 is a wasteful number, since it uses less digits than its factorization.

990918991818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191815579 (or 191815576 counting only the distinct ones).

The product of its (nonzero) digits is 30233088, while the sum is 72.

It can be divided in two parts, 99091 and 8991818, that added together give a palindrome (9090909).

The spelling of 990918991818 in words is "nine hundred ninety billion, nine hundred eighteen million, nine hundred ninety-one thousand, eight hundred eighteen".