9990545 has 4 divisors (see below), whose sum is σ = 11988660. Its totient is φ = 7992432.

The previous prime is 9990499. The next prime is 9990551. The reversal of 9990545 is 5450999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5450999 = 17 ⋅320647.

It can be written as a sum of positive squares in 2 ways, for example, as 5958481 + 4032064 = 2441^2 + 2008^2 .

It is a cyclic number.

It is not a de Polignac number, because 9990545 - 2⁸ = 9990289 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 999050 + ... + 999059.

It is an arithmetic number, because the mean of its divisors is an integer number (2997165).

Almost surely, 2^9990545 is an apocalyptic number.

It is an amenable number.

9990545 is a deficient number, since it is larger than the sum of its proper divisors (1998115).

9990545 is a wasteful number, since it uses less digits than its factorization.

9990545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1998114.

The product of its (nonzero) digits is 72900, while the sum is 41.

The square root of 9990545 is about 3160.7823398646. The cubic root of 9990545 is about 215.3755469920.

The spelling of 9990545 in words is "nine million, nine hundred ninety thousand, five hundred forty-five".