20420623 has 4 divisors (see below), whose sum is σ = 20431840. Its totient is φ = 20409408.

The previous prime is 20420591. The next prime is 20420627. The reversal of 20420623 is 32602402.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20420623 - 2⁵ = 20420591 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20420623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2178 + ... + 6751.

It is an arithmetic number, because the mean of its divisors is an integer number (5107960).

Almost surely, 2^20420623 is an apocalyptic number.

20420623 is a deficient number, since it is larger than the sum of its proper divisors (11217).

20420623 is an equidigital number, since it uses as much as digits as its factorization.

20420623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11216.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 20420623 is about 4518.9183440288. The cubic root of 20420623 is about 273.3314860408.

The spelling of 20420623 in words is "twenty million, four hundred twenty thousand, six hundred twenty-three".