9999591 has 16 divisors (see below), whose sum is σ = 15423744. Its totient is φ = 5644224.

The previous prime is 9999533. The next prime is 9999593. The reversal of 9999591 is 1959999.

9999591 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9999591 - 2⁷ = 9999463 is a prime.

9999591 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999593) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1126 + ... + 4611.

It is an arithmetic number, because the mean of its divisors is an integer number (963984).

Almost surely, 2^9999591 is an apocalyptic number.

9999591 is a deficient number, since it is larger than the sum of its proper divisors (5424153).

9999591 is a wasteful number, since it uses less digits than its factorization.

9999591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5830.

The product of its digits is 295245, while the sum is 51.

The square root of 9999591 is about 3162.2129909290. The cubic root of 9999591 is about 215.4405317505.

The spelling of 9999591 in words is "nine million, nine hundred ninety-nine thousand, five hundred ninety-one".