189231421 has 4 divisors (see below), whose sum is σ = 189318844. Its totient is φ = 189144000.

The previous prime is 189231407. The next prime is 189231443. The reversal of 189231421 is 124132981.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 122988100 + 66243321 = 11090^2 + 8139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-189231421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189231481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40380 + ... + 44821.

It is an arithmetic number, because the mean of its divisors is an integer number (47329711).

Almost surely, 2^189231421 is an apocalyptic number.

It is an amenable number.

189231421 is a deficient number, since it is larger than the sum of its proper divisors (87423).

189231421 is an equidigital number, since it uses as much as digits as its factorization.

189231421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87422.

The product of its digits is 3456, while the sum is 31.

The square root of 189231421 is about 13756.1412103831. The cubic root of 189231421 is about 574.1134881043.

The spelling of 189231421 in words is "one hundred eighty-nine million, two hundred thirty-one thousand, four hundred twenty-one".