20642023109 has 4 divisors (see below), whose sum is σ = 20654758860. Its totient is φ = 20629287360.

The previous prime is 20642023007. The next prime is 20642023121. The reversal of 20642023109 is 90132024602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16191799009 + 4450224100 = 127247^2 + 66710^2 .

It is a cyclic number.

It is not a de Polignac number, because 20642023109 - 2⁸ = 20642022853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20642026109) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 6365444 + ... + 6368685.

It is an arithmetic number, because the mean of its divisors is an integer number (5163689715).

Almost surely, 2^20642023109 is an apocalyptic number.

It is an amenable number.

20642023109 is a deficient number, since it is larger than the sum of its proper divisors (12735751).

20642023109 is a wasteful number, since it uses less digits than its factorization.

20642023109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12735750.

The product of its (nonzero) digits is 5184, while the sum is 29.

The spelling of 20642023109 in words is "twenty billion, six hundred forty-two million, twenty-three thousand, one hundred nine".