101990 has 32 divisors (see below), whose sum is σ = 221184. Its totient is φ = 33120.

The previous prime is 101987. The next prime is 101999. The reversal of 101990 is 99101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101999) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2147 + ... + 2193.

It is an arithmetic number, because the mean of its divisors is an integer number (6912).

2¹⁰¹⁹⁹⁰ is an apocalyptic number.

101990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

101990 is an abundant number, since it is smaller than the sum of its proper divisors (119194).

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

101990 is a wasteful number, since it uses less digits than its factorization.

101990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92.

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 101990 is about 319.3587324624. The cubic root of 101990 is about 46.7217603288.

It can be divided in two parts, 10 and 1990, that multiplied together give a triangular number (19900 = T₁₉₉).

The spelling of 101990 in words is "one hundred one thousand, nine hundred ninety".