21190 has 16 divisors (see below), whose sum is σ = 41328. Its totient is φ = 7776.

The previous prime is 21187. The next prime is 21191. The reversal of 21190 is 9112.

It is a super-2 number, since 2×21190² = 898032200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 21190.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49 + ... + 211.

It is an arithmetic number, because the mean of its divisors is an integer number (2583).

2²¹¹⁹⁰ is an apocalyptic number.

21190 is a deficient number, since it is larger than the sum of its proper divisors (20138).

21190 is a wasteful number, since it uses less digits than its factorization.

21190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 21190 is about 145.5678535941. The cubic root of 21190 is about 27.6721977297.

The spelling of 21190 in words is "twenty-one thousand, one hundred ninety".