990971 has 4 divisors (see below), whose sum is σ = 1017792. Its totient is φ = 964152.

The previous prime is 990967. The next prime is 990973. The reversal of 990971 is 179099.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 990971 - 2² = 990967 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (990973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13355 + ... + 13428.

It is an arithmetic number, because the mean of its divisors is an integer number (254448).

2⁹⁹⁰⁹⁷¹ is an apocalyptic number.

990971 is a deficient number, since it is larger than the sum of its proper divisors (26821).

990971 is a wasteful number, since it uses less digits than its factorization.

990971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26820.

The product of its (nonzero) digits is 5103, while the sum is 35.

The square root of 990971 is about 995.4752633793. The cubic root of 990971 is about 99.6981229528.

The spelling of 990971 in words is "nine hundred ninety thousand, nine hundred seventy-one".