97618128721 has 9 divisors (see below), whose sum is σ = 97989147099. Its totient is φ = 97248513384.

The previous prime is 97618128703. The next prime is 97618128743. The reversal of 97618128721 is 12782181679.

The square root of 97618128721 is 312439.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 65420850625 + 32197278096 = 255775^2 + 179436^2 .

It is not a de Polignac number, because 97618128721 - 2²³ = 97609740113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (97618128791) 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 8 ways as a sum of consecutive naturals, for example, 124037890 + ... + 124038676.

It is an arithmetic number, because the mean of its divisors is an integer number (10887683011).

Almost surely, 2^97618128721 is an apocalyptic number.

97618128721 is the 312439-th square number.

97618128721 is the 156220-th centered octagonal number.

It is an amenable number.

97618128721 is a deficient number, since it is larger than the sum of its proper divisors (371018378).

97618128721 is an frugal number, since it uses more digits than its factorization.

97618128721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2368 (or 1184 counting only the distinct ones).

The product of its digits is 677376, while the sum is 52.

The spelling of 97618128721 in words is "ninety-seven billion, six hundred eighteen million, one hundred twenty-eight thousand, seven hundred twenty-one".