189123621 has 4 divisors (see below), whose sum is σ = 252164832. Its totient is φ = 126082412.

The previous prime is 189123619. The next prime is 189123637. The reversal of 189123621 is 126321981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 189123621 - 2¹ = 189123619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189123601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31520601 + ... + 31520606.

It is an arithmetic number, because the mean of its divisors is an integer number (63041208).

Almost surely, 2^189123621 is an apocalyptic number.

It is an amenable number.

189123621 is a deficient number, since it is larger than the sum of its proper divisors (63041211).

189123621 is an equidigital number, since it uses as much as digits as its factorization.

189123621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63041210.

The product of its digits is 5184, while the sum is 33.

The square root of 189123621 is about 13752.2224022156. Note that the first 3 decimals coincide. The cubic root of 189123621 is about 574.0044484433.

The spelling of 189123621 in words is "one hundred eighty-nine million, one hundred twenty-three thousand, six hundred twenty-one".