990749 has 4 divisors (see below), whose sum is σ = 1017564. Its totient is φ = 963936.

The previous prime is 990733. The next prime is 990761. The reversal of 990749 is 947099.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 947099 = 353 ⋅2683.

It can be written as a sum of positive squares in 2 ways, for example, as 525625 + 465124 = 725^2 + 682^2 .

It is a cyclic number.

It is not a de Polignac number, because 990749 - 2⁴ = 990733 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 (990719) 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, 13352 + ... + 13425.

It is an arithmetic number, because the mean of its divisors is an integer number (254391).

2⁹⁹⁰⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

990749 is a deficient number, since it is larger than the sum of its proper divisors (26815).

990749 is a wasteful number, since it uses less digits than its factorization.

990749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26814.

The product of its (nonzero) digits is 20412, while the sum is 38.

The square root of 990749 is about 995.3637526050. The cubic root of 990749 is about 99.6906775159.

The spelling of 990749 in words is "nine hundred ninety thousand, seven hundred forty-nine".