121565065999 has 4 divisors (see below), whose sum is σ = 130916224936. Its totient is φ = 112213907064.

The previous prime is 121565065907. The next prime is 121565066003. The reversal of 121565065999 is 999560565121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 999560565121 = 127163 ⋅7860467.

It is a cyclic number.

It is not a de Polignac number, because 121565065999 - 2²¹ = 121562968847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121565065199) 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, 4675579449 + ... + 4675579474.

It is an arithmetic number, because the mean of its divisors is an integer number (32729056234).

Almost surely, 2^121565065999 is an apocalyptic number.

121565065999 is a deficient number, since it is larger than the sum of its proper divisors (9351158937).

121565065999 is an equidigital number, since it uses as much as digits as its factorization.

121565065999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9351158936.

The product of its (nonzero) digits is 6561000, while the sum is 58.

The spelling of 121565065999 in words is "one hundred twenty-one billion, five hundred sixty-five million, sixty-five thousand, nine hundred ninety-nine".