165435421 has 2 divisors, whose sum is σ = 165435422. Its totient is φ = 165435420.

The previous prime is 165435379. The next prime is 165435443. The reversal of 165435421 is 124534561.

It is a happy number.

165435421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163558521 + 1876900 = 12789^2 + 1370^2 .

It is a cyclic number.

It is not a de Polignac number, because 165435421 - 2⁷ = 165435293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165435461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82717710 + 82717711.

It is an arithmetic number, because the mean of its divisors is an integer number (82717711).

Almost surely, 2^165435421 is an apocalyptic number.

It is an amenable number.

165435421 is a deficient number, since it is larger than the sum of its proper divisors (1).

165435421 is an equidigital number, since it uses as much as digits as its factorization.

165435421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14400, while the sum is 31.

The square root of 165435421 is about 12862.1701512614. The cubic root of 165435421 is about 548.9626961071.

Adding to 165435421 its reverse (124534561), we get a palindrome (289969982).

The spelling of 165435421 in words is "one hundred sixty-five million, four hundred thirty-five thousand, four hundred twenty-one".