20105203123550 has 48 divisors (see below), whose sum is σ = 39392796668400. Its totient is φ = 7613215372800.

The previous prime is 20105203123501. The next prime is 20105203123571. The reversal of 20105203123550 is 5532130250102.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6481985 + ... + 9067884.

It is an arithmetic number, because the mean of its divisors is an integer number (820683263925).

Almost surely, 2^{20105203123550} is an apocalyptic number.

20105203123550 is a deficient number, since it is larger than the sum of its proper divisors (19287593544850).

20105203123550 is a wasteful number, since it uses less digits than its factorization.

20105203123550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15551261 (or 15551256 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 29.

Adding to 20105203123550 its reverse (5532130250102), we get a palindrome (25637333373652).

The spelling of 20105203123550 in words is "twenty trillion, one hundred five billion, two hundred three million, one hundred twenty-three thousand, five hundred fifty".