121665566123 has 2 divisors, whose sum is σ = 121665566124. Its totient is φ = 121665566122.

The previous prime is 121665566089. The next prime is 121665566201. The reversal of 121665566123 is 321665566121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121665566123 - 2²⁰ = 121664517547 is a prime.

It is a super-2 number, since 2×121665566123² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (121665566023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60832783061 + 60832783062.

It is an arithmetic number, because the mean of its divisors is an integer number (60832783062).

Almost surely, 2^121665566123 is an apocalyptic number.

121665566123 is a deficient number, since it is larger than the sum of its proper divisors (1).

121665566123 is an equidigital number, since it uses as much as digits as its factorization.

121665566123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 388800, while the sum is 44.

The spelling of 121665566123 in words is "one hundred twenty-one billion, six hundred sixty-five million, five hundred sixty-six thousand, one hundred twenty-three".