121989740805 has 36 divisors (see below), whose sum is σ = 213863464620. Its totient is φ = 64318514304.

The previous prime is 121989740791. The next prime is 121989740813. The reversal of 121989740805 is 508047989121.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 33170244129 + 88819496676 = 182127^2 + 298026^2 .

It is not a de Polignac number, because 121989740805 - 2¹¹ = 121989738757 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 22100836 + ... + 22106354.

It is an arithmetic number, because the mean of its divisors is an integer number (5940651795).

Almost surely, 2^121989740805 is an apocalyptic number.

121989740805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121989740805 is a deficient number, since it is larger than the sum of its proper divisors (91873723815).

121989740805 is an frugal number, since it uses more digits than its factorization.

121989740805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11138 (or 5616 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The spelling of 121989740805 in words is "one hundred twenty-one billion, nine hundred eighty-nine million, seven hundred forty thousand, eight hundred five".