993990 has 32 divisors (see below), whose sum is σ = 2527200. Its totient is φ = 249344.

The previous prime is 993983. The next prime is 993997. The reversal of 993990 is 99399.

It is an interprime number because it is at equal distance from previous prime (993983) and next prime (993997).

It is a super-2 number, since 2×993990² = 1976032240200, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (993997) by changing a digit.

993990 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 in 15 ways as a sum of consecutive naturals, for example, 465 + ... + 1484.

It is an arithmetic number, because the mean of its divisors is an integer number (78975).

2⁹⁹³⁹⁹⁰ is an apocalyptic number.

993990 is an abundant number, since it is smaller than the sum of its proper divisors (1533210).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

993990 is a wasteful number, since it uses less digits than its factorization.

993990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1976.

The product of its (nonzero) digits is 19683, while the sum is 39.

The square root of 993990 is about 996.9904713687. The cubic root of 993990 is about 99.7992639868.

The spelling of 993990 in words is "nine hundred ninety-three thousand, nine hundred ninety".