9999405 has 24 divisors (see below), whose sum is σ = 18666648. Its totient is φ = 4922496.

The previous prime is 9999401. The next prime is 9999419. The reversal of 9999405 is 5049999.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 227529 + 9771876 = 477^2 + 3126^2 .

It is not a de Polignac number, because 9999405 - 2² = 9999401 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999401) 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, 7962 + ... + 9131.

It is an arithmetic number, because the mean of its divisors is an integer number (777777).

Almost surely, 2^9999405 is an apocalyptic number.

It is an amenable number.

9999405 is a deficient number, since it is larger than the sum of its proper divisors (8667243).

9999405 is a wasteful number, since it uses less digits than its factorization.

9999405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17117 (or 17114 counting only the distinct ones).

The product of its (nonzero) digits is 131220, while the sum is 45.

The square root of 9999405 is about 3162.1835810085. The cubic root of 9999405 is about 215.4391959563.

It can be divided in two parts, 9999 and 405, that added together give a square (10404 = 102²).

The spelling of 9999405 in words is "nine million, nine hundred ninety-nine thousand, four hundred five".