195990 has 32 divisors (see below), whose sum is σ = 483840. Its totient is φ = 50784.

The previous prime is 195977. The next prime is 195991. The reversal of 195990 is 99591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (195991) by changing a digit.

195990 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1341 + ... + 1479.

It is an arithmetic number, because the mean of its divisors is an integer number (15120).

2¹⁹⁵⁹⁹⁰ is an apocalyptic number.

195990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 195990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (241920).

195990 is an abundant number, since it is smaller than the sum of its proper divisors (287850).

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

195990 is a wasteful number, since it uses less digits than its factorization.

195990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196.

The product of its (nonzero) digits is 3645, while the sum is 33.

The square root of 195990 is about 442.7075784307. The cubic root of 195990 is about 58.0868694301.

The spelling of 195990 in words is "one hundred ninety-five thousand, nine hundred ninety".