20503161305 has 32 divisors (see below), whose sum is σ = 27712032768. Its totient is φ = 14432947200.

The previous prime is 20503161281. The next prime is 20503161319. The reversal of 20503161305 is 50316130502.

It is not a de Polignac number, because 20503161305 - 2²² = 20498967001 is a prime.

It is a super-3 number, since 3×20503161305³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 250589 + ... + 322181.

It is an arithmetic number, because the mean of its divisors is an integer number (866001024).

Almost surely, 2^20503161305 is an apocalyptic number.

It is an amenable number.

20503161305 is a deficient number, since it is larger than the sum of its proper divisors (7208871463).

20503161305 is a wasteful number, since it uses less digits than its factorization.

20503161305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71777.

The product of its (nonzero) digits is 2700, while the sum is 26.

Adding to 20503161305 its reverse (50316130502), we get a palindrome (70819291807).

The spelling of 20503161305 in words is "twenty billion, five hundred three million, one hundred sixty-one thousand, three hundred five".