20400423 has 8 divisors (see below), whose sum is σ = 27374448. Its totient is φ = 13513344.

The previous prime is 20400421. The next prime is 20400437. The reversal of 20400423 is 32400402.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20400423 - 2¹ = 20400421 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400421) 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 7 ways as a sum of consecutive naturals, for example, 21186 + ... + 22127.

It is an arithmetic number, because the mean of its divisors is an integer number (3421806).

Almost surely, 2^20400423 is an apocalyptic number.

20400423 is a deficient number, since it is larger than the sum of its proper divisors (6974025).

20400423 is a wasteful number, since it uses less digits than its factorization.

20400423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43473.

The product of its (nonzero) digits is 192, while the sum is 15.

The square root of 20400423 is about 4516.6827428988. The cubic root of 20400423 is about 273.2413301631.

Adding to 20400423 its reverse (32400402), we get a palindrome (52800825).

The spelling of 20400423 in words is "twenty million, four hundred thousand, four hundred twenty-three".