990247 has 4 divisors (see below), whose sum is σ = 1013320. Its totient is φ = 967176.

The previous prime is 990239. The next prime is 990259. The reversal of 990247 is 742099.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 742099 = 197 ⋅3767.

It is a cyclic number.

It is not a de Polignac number, because 990247 - 2³ = 990239 is a prime.

It is a Duffinian number.

990247 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11472 + ... + 11557.

It is an arithmetic number, because the mean of its divisors is an integer number (253330).

2⁹⁹⁰²⁴⁷ is an apocalyptic number.

990247 is a deficient number, since it is larger than the sum of its proper divisors (23073).

990247 is a wasteful number, since it uses less digits than its factorization.

990247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23072.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 990247 is about 995.1115515358. Note that the first 3 decimals coincide. The cubic root of 990247 is about 99.6738373358.

The spelling of 990247 in words is "nine hundred ninety thousand, two hundred forty-seven".