20423181 has 4 divisors (see below), whose sum is σ = 27230912. Its totient is φ = 13615452.

The previous prime is 20423177. The next prime is 20423201. The reversal of 20423181 is 18132402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20423181 - 2² = 20423177 is a prime.

It is a super-2 number, since 2×20423181² = 834212644317522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20427181) 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, 3403861 + ... + 3403866.

It is an arithmetic number, because the mean of its divisors is an integer number (6807728).

Almost surely, 2^20423181 is an apocalyptic number.

It is an amenable number.

20423181 is a deficient number, since it is larger than the sum of its proper divisors (6807731).

20423181 is an equidigital number, since it uses as much as digits as its factorization.

20423181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6807730.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 20423181 is about 4519.2013674985. The cubic root of 20423181 is about 273.3428985680.

Adding to 20423181 its reverse (18132402), we get a palindrome (38555583).

The spelling of 20423181 in words is "twenty million, four hundred twenty-three thousand, one hundred eighty-one".