171589421 has 2 divisors, whose sum is σ = 171589422. Its totient is φ = 171589420.

The previous prime is 171589403. The next prime is 171589423. The reversal of 171589421 is 124985171.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166771396 + 4818025 = 12914^2 + 2195^2 .

It is a cyclic number.

It is not a de Polignac number, because 171589421 - 2²² = 167395117 is a prime.

Together with 171589423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171589423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85794710 + 85794711.

It is an arithmetic number, because the mean of its divisors is an integer number (85794711).

Almost surely, 2^171589421 is an apocalyptic number.

It is an amenable number.

171589421 is a deficient number, since it is larger than the sum of its proper divisors (1).

171589421 is an equidigital number, since it uses as much as digits as its factorization.

171589421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 38.

The square root of 171589421 is about 13099.2145184358. The cubic root of 171589421 is about 555.6869139889.

The spelling of 171589421 in words is "one hundred seventy-one million, five hundred eighty-nine thousand, four hundred twenty-one".