20658023 has 4 divisors (see below), whose sum is σ = 20705520. Its totient is φ = 20610528.

The previous prime is 20657999. The next prime is 20658037. The reversal of 20658023 is 32085602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32085602 = 2 ⋅16042801.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20658023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20657983 and 20658001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20658223) 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, 23090 + ... + 23967.

It is an arithmetic number, because the mean of its divisors is an integer number (5176380).

Almost surely, 2^20658023 is an apocalyptic number.

20658023 is a deficient number, since it is larger than the sum of its proper divisors (47497).

20658023 is an equidigital number, since it uses as much as digits as its factorization.

20658023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47496.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 20658023 is about 4545.1097896531. The cubic root of 20658023 is about 274.3866130240.

The spelling of 20658023 in words is "twenty million, six hundred fifty-eight thousand, twenty-three".