21109565740180 has 24 divisors (see below), whose sum is σ = 44612445309768. Its totient is φ = 8390043961728.

The previous prime is 21109565740099. The next prime is 21109565740189. The reversal of 21109565740180 is 8104756590112.

It can be written as a sum of positive squares in 4 ways, for example, as 2051643710736 + 19057922029444 = 1432356^2 + 4365538^2 .

It is a super-2 number, since 2×21109565740180² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21109565740189) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3361392679 + ... + 3361398958.

It is an arithmetic number, because the mean of its divisors is an integer number (1858851887907).

Almost surely, 2^{21109565740180} is an apocalyptic number.

21109565740180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21109565740180 is an abundant number, since it is smaller than the sum of its proper divisors (23502879569588).

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

21109565740180 is a wasteful number, since it uses less digits than its factorization.

21109565740180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6722791803 (or 6722791801 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 49.

The spelling of 21109565740180 in words is "twenty-one trillion, one hundred nine billion, five hundred sixty-five million, seven hundred forty thousand, one hundred eighty".