121579928065 has 4 divisors (see below), whose sum is σ = 145895913684. Its totient is φ = 97263942448.

The previous prime is 121579928047. The next prime is 121579928069. The reversal of 121579928065 is 560829975121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 35642419264 + 85937508801 = 188792^2 + 293151^2 .

It is a cyclic number.

It is not a de Polignac number, because 121579928065 - 2²³ = 121571539457 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121579927997 and 121579928015.

It is not an unprimeable number, because it can be changed into a prime (121579928069) 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, 12157992802 + ... + 12157992811.

It is an arithmetic number, because the mean of its divisors is an integer number (36473978421).

Almost surely, 2^121579928065 is an apocalyptic number.

It is an amenable number.

121579928065 is a deficient number, since it is larger than the sum of its proper divisors (24315985619).

121579928065 is an equidigital number, since it uses as much as digits as its factorization.

121579928065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24315985618.

The product of its (nonzero) digits is 2721600, while the sum is 55.

The spelling of 121579928065 in words is "one hundred twenty-one billion, five hundred seventy-nine million, nine hundred twenty-eight thousand, sixty-five".