165121423 has 2 divisors, whose sum is σ = 165121424. Its totient is φ = 165121422.

The previous prime is 165121403. The next prime is 165121427. The reversal of 165121423 is 324121561.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165121423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165121427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82560711 + 82560712.

It is an arithmetic number, because the mean of its divisors is an integer number (82560712).

Almost surely, 2^165121423 is an apocalyptic number.

165121423 is a deficient number, since it is larger than the sum of its proper divisors (1).

165121423 is an equidigital number, since it uses as much as digits as its factorization.

165121423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 25.

The square root of 165121423 is about 12849.9580933169. The cubic root of 165121423 is about 548.6151640045.

Adding to 165121423 its reverse (324121561), we get a palindrome (489242984).

The spelling of 165121423 in words is "one hundred sixty-five million, one hundred twenty-one thousand, four hundred twenty-three".