20165623 has 2 divisors, whose sum is σ = 20165624. Its totient is φ = 20165622.

The previous prime is 20165611. The next prime is 20165627. The reversal of 20165623 is 32656102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20165623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20165627) 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, 10082811 + 10082812.

It is an arithmetic number, because the mean of its divisors is an integer number (10082812).

Almost surely, 2^20165623 is an apocalyptic number.

20165623 is a deficient number, since it is larger than the sum of its proper divisors (1).

20165623 is an equidigital number, since it uses as much as digits as its factorization.

20165623 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 20165623 is about 4490.6149912902. The cubic root of 20165623 is about 272.1889861285.

The spelling of 20165623 in words is "twenty million, one hundred sixty-five thousand, six hundred twenty-three".