20431235155503 has 16 divisors (see below), whose sum is σ = 27482389880960. Its totient is φ = 13500771647904.

The previous prime is 20431235155321. The next prime is 20431235155537. The reversal of 20431235155503 is 30555153213402.

It is not a de Polignac number, because 20431235155503 - 2⁹ = 20431235154991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20431230155503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39708301 + ... + 40219542.

It is an arithmetic number, because the mean of its divisors is an integer number (1717649367560).

Almost surely, 2^{20431235155503} is an apocalyptic number.

20431235155503 is a deficient number, since it is larger than the sum of its proper divisors (7051154725457).

20431235155503 is a wasteful number, since it uses less digits than its factorization.

20431235155503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79928598.

The product of its (nonzero) digits is 270000, while the sum is 39.

Adding to 20431235155503 its reverse (30555153213402), we get a palindrome (50986388368905).

The spelling of 20431235155503 in words is "twenty trillion, four hundred thirty-one billion, two hundred thirty-five million, one hundred fifty-five thousand, five hundred three".