189621 has 10 divisors (see below), whose sum is σ = 283382. Its totient is φ = 126360.

The previous prime is 189619. The next prime is 189643. The reversal of 189621 is 126981.

189621 is nontrivially palindromic in base 8.

It can be written as a sum of positive squares in only one way, i.e., 171396 + 18225 = 414^2 + 135^2 .

It is not a de Polignac number, because 189621 - 2¹ = 189619 is a prime.

It is a super-2 number, since 2×189621² = 71912247282, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

189621 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189661) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1090 + ... + 1251.

2¹⁸⁹⁶²¹ is an apocalyptic number.

It is an amenable number.

189621 is a deficient number, since it is larger than the sum of its proper divisors (93761).

189621 is an equidigital number, since it uses as much as digits as its factorization.

189621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2353 (or 2344 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 189621 is about 435.4549345225. The cubic root of 189621 is about 57.4507202222.

The spelling of 189621 in words is "one hundred eighty-nine thousand, six hundred twenty-one".