990579871 has 4 divisors (see below), whose sum is σ = 991474200. Its totient is φ = 989685544.

The previous prime is 990579841. The next prime is 990579881. The reversal of 990579871 is 178975099.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990579871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990579841) 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, 445501 + ... + 447718.

It is an arithmetic number, because the mean of its divisors is an integer number (247868550).

Almost surely, 2^990579871 is an apocalyptic number.

990579871 is a deficient number, since it is larger than the sum of its proper divisors (894329).

990579871 is a wasteful number, since it uses less digits than its factorization.

990579871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 894328.

The product of its (nonzero) digits is 1428840, while the sum is 55.

The square root of 990579871 is about 31473.4788512487. The cubic root of 990579871 is about 996.8500452030.

The spelling of 990579871 in words is "nine hundred ninety million, five hundred seventy-nine thousand, eight hundred seventy-one".