121613570721 has 8 divisors (see below), whose sum is σ = 180168252960. Its totient is φ = 81075713796.

The previous prime is 121613570711. The next prime is 121613570723. The reversal of 121613570721 is 127075316121.

121613570721 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 13 + 570 + 72 + 1 = 666.

It is not a de Polignac number, because 121613570721 - 2⁷ = 121613570593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121613570723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2252103135 + ... + 2252103188.

It is an arithmetic number, because the mean of its divisors is an integer number (22521031620).

Almost surely, 2^121613570721 is an apocalyptic number.

It is an amenable number.

121613570721 is a deficient number, since it is larger than the sum of its proper divisors (58554682239).

121613570721 is an equidigital number, since it uses as much as digits as its factorization.

121613570721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4504206332 (or 4504206326 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 36.

Adding to 121613570721 its reverse (127075316121), we get a palindrome (248688886842).

The spelling of 121613570721 in words is "one hundred twenty-one billion, six hundred thirteen million, five hundred seventy thousand, seven hundred twenty-one".