20420023 has 4 divisors (see below), whose sum is σ = 21990808. Its totient is φ = 18849240.

The previous prime is 20420011. The next prime is 20420027. The reversal of 20420023 is 32002402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32002402 = 2 ⋅16001201.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20420023 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1570771 = 20420023 / (2 + 0 + 4 + 2 + 0 + 0 + 2 + 3).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20419985 and 20420012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 785373 + ... + 785398.

It is an arithmetic number, because the mean of its divisors is an integer number (5497702).

Almost surely, 2^20420023 is an apocalyptic number.

20420023 is a deficient number, since it is larger than the sum of its proper divisors (1570785).

20420023 is a wasteful number, since it uses less digits than its factorization.

20420023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1570784.

The product of its (nonzero) digits is 96, while the sum is 13.

The square root of 20420023 is about 4518.8519559729. The cubic root of 20420023 is about 273.3288090004.

Adding to 20420023 its reverse (32002402), we get a palindrome (52422425).

The spelling of 20420023 in words is "twenty million, four hundred twenty thousand, twenty-three".