999100009800 has 72 divisors (see below), whose sum is σ = 3355310872290. Its totient is φ = 266426668800.

The previous prime is 999100009777. The next prime is 999100009811. The reversal of 999100009800 is 8900001999.

It can be written as a sum of positive squares in 3 ways, for example, as 914023954116 + 85076055684 = 956046^2 + 291678^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 277525981 + ... + 277529580.

Almost surely, 2^999100009800 is an apocalyptic number.

999100009800 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

999100009800 is an abundant number, since it is smaller than the sum of its proper divisors (2356210862490).

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

999100009800 is a wasteful number, since it uses less digits than its factorization.

999100009800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555055583 (or 555055571 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

The spelling of 999100009800 in words is "nine hundred ninety-nine billion, one hundred million, nine thousand, eight hundred".