991384 has 8 divisors (see below), whose sum is σ = 1858860. Its totient is φ = 495688.

The previous prime is 991381. The next prime is 991387. The reversal of 991384 is 483199.

It is an interprime number because it is at equal distance from previous prime (991381) and next prime (991387).

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-3 number, since 3×991384³ = 2923122200265933312, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61954 + ... + 61969.

2⁹⁹¹³⁸⁴ is an apocalyptic number.

It is an amenable number.

991384 is a deficient number, since it is larger than the sum of its proper divisors (867476).

991384 is a wasteful number, since it uses less digits than its factorization.

991384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123929 (or 123925 counting only the distinct ones).

The product of its digits is 7776, while the sum is 34.

The square root of 991384 is about 995.6826803756. The cubic root of 991384 is about 99.7119711906.

The spelling of 991384 in words is "nine hundred ninety-one thousand, three hundred eighty-four".