121766566417 has 4 divisors (see below), whose sum is σ = 128929305636. Its totient is φ = 114603827200.

The previous prime is 121766566309. The next prime is 121766566421. The reversal of 121766566417 is 714665667121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 714665667121 = 7 ⋅102095095303.

It can be written as a sum of positive squares in 2 ways, for example, as 63016562961 + 58750003456 = 251031^2 + 242384^2 .

It is not a de Polignac number, because 121766566417 - 2¹⁵ = 121766533649 is a prime.

It is a super-3 number, since 3×121766566417³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121766566457) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3581369584 + ... + 3581369617.

It is an arithmetic number, because the mean of its divisors is an integer number (32232326409).

Almost surely, 2^121766566417 is an apocalyptic number.

121766566417 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

121766566417 is a deficient number, since it is larger than the sum of its proper divisors (7162739219).

121766566417 is an equidigital number, since it uses as much as digits as its factorization.

121766566417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7162739218.

The product of its digits is 2540160, while the sum is 52.

The spelling of 121766566417 in words is "one hundred twenty-one billion, seven hundred sixty-six million, five hundred sixty-six thousand, four hundred seventeen".