189505821 has 8 divisors (see below), whose sum is σ = 260825344. Its totient is φ = 122261760.

The previous prime is 189505819. The next prime is 189505847. The reversal of 189505821 is 128505981.

189505821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 189505821 - 2¹ = 189505819 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 189505821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189505801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1018756 + ... + 1018941.

It is an arithmetic number, because the mean of its divisors is an integer number (32603168).

Almost surely, 2^189505821 is an apocalyptic number.

It is an amenable number.

189505821 is a deficient number, since it is larger than the sum of its proper divisors (71319523).

189505821 is a wasteful number, since it uses less digits than its factorization.

189505821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2037731.

The product of its (nonzero) digits is 28800, while the sum is 39.

The square root of 189505821 is about 13766.1113245535. Note that the first 3 decimals coincide. The cubic root of 189505821 is about 574.3908568676.

The spelling of 189505821 in words is "one hundred eighty-nine million, five hundred five thousand, eight hundred twenty-one".