9999810 has 24 divisors (see below), whose sum is σ = 25999740. Its totient is φ = 2666592.

The previous prime is 9999761. The next prime is 9999823. The reversal of 9999810 is 189999.

It can be written as a sum of positive squares in 2 ways, for example, as 9678321 + 321489 = 3111^2 + 567^2 .

It is a super-2 number, since 2×9999810² = 199992400072200, which contains 22 as substring.

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

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55465 + ... + 55644.

Almost surely, 2^9999810 is an apocalyptic number.

9999810 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

9999810 is an abundant number, since it is smaller than the sum of its proper divisors (15999930).

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

9999810 is a wasteful number, since it uses less digits than its factorization.

9999810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111122 (or 111119 counting only the distinct ones).

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

The square root of 9999810 is about 3162.2476183879. The cubic root of 9999810 is about 215.4421045192.

The spelling of 9999810 in words is "nine million, nine hundred ninety-nine thousand, eight hundred ten".