20355823 has 4 divisors (see below), whose sum is σ = 20371680. Its totient is φ = 20339968.

The previous prime is 20355791. The next prime is 20355827. The reversal of 20355823 is 32855302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20355823 - 2⁵ = 20355791 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 20355791 and 20355800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20355827) 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, 5815 + ... + 8632.

It is an arithmetic number, because the mean of its divisors is an integer number (5092920).

Almost surely, 2^20355823 is an apocalyptic number.

20355823 is a deficient number, since it is larger than the sum of its proper divisors (15857).

20355823 is a wasteful number, since it uses less digits than its factorization.

20355823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15856.

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 20355823 is about 4511.7427896546. The cubic root of 20355823 is about 273.0420621545.

The spelling of 20355823 in words is "twenty million, three hundred fifty-five thousand, eight hundred twenty-three".