990538 has 4 divisors (see below), whose sum is σ = 1485810. Its totient is φ = 495268.

The previous prime is 990529. The next prime is 990547. The reversal of 990538 is 835099.

990538 is nontrivially palindromic in base 3.

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

It is an interprime number because it is at equal distance from previous prime (990529) and next prime (990547).

It can be written as a sum of positive squares in only one way, i.e., 986049 + 4489 = 993^2 + 67^2 .

It is an unprimeable number.

990538 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 247633 + ... + 247636.

2⁹⁹⁰⁵³⁸ is an apocalyptic number.

990538 is a deficient number, since it is larger than the sum of its proper divisors (495272).

990538 is a wasteful number, since it uses less digits than its factorization.

990538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495271.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 990538 is about 995.2577555588. The cubic root of 990538 is about 99.6835999660.

The spelling of 990538 in words is "nine hundred ninety thousand, five hundred thirty-eight".