20509351775 has 18 divisors (see below), whose sum is σ = 27953742096. Its totient is φ = 14915890000.

The previous prime is 20509351717. The next prime is 20509351801. The reversal of 20509351775 is 57715390502.

It is not a de Polignac number, because 20509351775 - 2¹² = 20509347679 is a prime.

It is a Duffinian number.

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 17 ways as a sum of consecutive naturals, for example, 3386951 + ... + 3393000.

It is an arithmetic number, because the mean of its divisors is an integer number (1552985672).

Almost surely, 2^20509351775 is an apocalyptic number.

20509351775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20509351775 is a deficient number, since it is larger than the sum of its proper divisors (7444390321).

20509351775 is a wasteful number, since it uses less digits than its factorization.

20509351775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6779983 (or 6779967 counting only the distinct ones).

The product of its (nonzero) digits is 330750, while the sum is 44.

The spelling of 20509351775 in words is "twenty billion, five hundred nine million, three hundred fifty-one thousand, seven hundred seventy-five".