20355440423 has 2 divisors, whose sum is σ = 20355440424. Its totient is φ = 20355440422.

The previous prime is 20355440401. The next prime is 20355440429. The reversal of 20355440423 is 32404455302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20355440423 - 2⁶ = 20355440359 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20355440423.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20355440429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10177720211 + 10177720212.

It is an arithmetic number, because the mean of its divisors is an integer number (10177720212).

Almost surely, 2^20355440423 is an apocalyptic number.

20355440423 is a deficient number, since it is larger than the sum of its proper divisors (1).

20355440423 is an equidigital number, since it uses as much as digits as its factorization.

20355440423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 57600, while the sum is 32.

Adding to 20355440423 its reverse (32404455302), we get a palindrome (52759895725).

The spelling of 20355440423 in words is "twenty billion, three hundred fifty-five million, four hundred forty thousand, four hundred twenty-three".