20979559100 has 18 divisors (see below), whose sum is σ = 45525643464. Its totient is φ = 8391823600.

The previous prime is 20979559091. The next prime is 20979559109. The reversal of 20979559100 is 195597902.

It is an interprime number because it is at equal distance from previous prime (20979559091) and next prime (20979559109).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20979559109) 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 5 ways as a sum of consecutive naturals, for example, 104897696 + ... + 104897895.

Almost surely, 2^20979559100 is an apocalyptic number.

20979559100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20979559100 is an abundant number, since it is smaller than the sum of its proper divisors (24546084364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20979559100 is a wasteful number, since it uses less digits than its factorization.

20979559100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209795605 (or 209795598 counting only the distinct ones).

The product of its (nonzero) digits is 255150, while the sum is 47.

The spelling of 20979559100 in words is "twenty billion, nine hundred seventy-nine million, five hundred fifty-nine thousand, one hundred".