121161720566651 has 4 divisors (see below), whose sum is σ = 121162347738432. Its totient is φ = 121161093394872.

The previous prime is 121161720566633. The next prime is 121161720566671. The reversal of 121161720566651 is 156665027161121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121161720566651 - 2³⁸ = 120886842659707 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121161720566651.

It is not an unprimeable number, because it can be changed into a prime (121161720566611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313296020 + ... + 313682513.

It is an arithmetic number, because the mean of its divisors is an integer number (30290586934608).

Almost surely, 2^{121161720566651} is an apocalyptic number.

121161720566651 is a deficient number, since it is larger than the sum of its proper divisors (627171781).

121161720566651 is an equidigital number, since it uses as much as digits as its factorization.

121161720566651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627171780.

The product of its (nonzero) digits is 907200, while the sum is 50.

The spelling of 121161720566651 in words is "one hundred twenty-one trillion, one hundred sixty-one billion, seven hundred twenty million, five hundred sixty-six thousand, six hundred fifty-one".