9999945 has 24 divisors (see below), whose sum is σ = 17409600. Its totient is φ = 5309856.

The previous prime is 9999943. The next prime is 9999971. The reversal of 9999945 is 5499999.

It is a happy number.

It is not a de Polignac number, because 9999945 - 2¹ = 9999943 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 9999891 and 9999900.

It is not an unprimeable number, because it can be changed into a prime (9999943) 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, 15846 + ... + 16464.

It is an arithmetic number, because the mean of its divisors is an integer number (725400).

Almost surely, 2^9999945 is an apocalyptic number.

It is an amenable number.

9999945 is a deficient number, since it is larger than the sum of its proper divisors (7409655).

9999945 is a wasteful number, since it uses less digits than its factorization.

9999945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 989 (or 986 counting only the distinct ones).

The product of its digits is 1180980, while the sum is 54.

The square root of 9999945 is about 3162.2689638929. The cubic root of 9999945 is about 215.4430740228.

Adding to 9999945 its sum of digits (54), we get a palindrome (9999999).

It can be divided in two parts, 999994 and 5, that added together give a palindrome (999999).

The spelling of 9999945 in words is "nine million, nine hundred ninety-nine thousand, nine hundred forty-five".