20616981109 has 16 divisors (see below), whose sum is σ = 21750261120. Its totient is φ = 19503728640.

The previous prime is 20616981103. The next prime is 20616981137. The reversal of 20616981109 is 90118961602.

It is a cyclic number.

It is not a de Polignac number, because 20616981109 - 2³ = 20616981101 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 (20616981101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4859229 + ... + 4863469.

It is an arithmetic number, because the mean of its divisors is an integer number (1359391320).

Almost surely, 2^20616981109 is an apocalyptic number.

It is an amenable number.

20616981109 is a deficient number, since it is larger than the sum of its proper divisors (1133280011).

20616981109 is a wasteful number, since it uses less digits than its factorization.

20616981109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6540.

The product of its (nonzero) digits is 46656, while the sum is 43.

The spelling of 20616981109 in words is "twenty billion, six hundred sixteen million, nine hundred eighty-one thousand, one hundred nine".