97666561 has 4 divisors (see below), whose sum is σ = 97703172. Its totient is φ = 97629952.

The previous prime is 97666559. The next prime is 97666567. The reversal of 97666561 is 16566679.

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 12215025 + 85451536 = 3495^2 + 9244^2 .

It is a cyclic number.

It is not a de Polignac number, because 97666561 - 2¹ = 97666559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (97666567) 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, 13960 + ... + 19753.

It is an arithmetic number, because the mean of its divisors is an integer number (24425793).

Almost surely, 2^97666561 is an apocalyptic number.

It is an amenable number.

97666561 is a deficient number, since it is larger than the sum of its proper divisors (36611).

97666561 is a wasteful number, since it uses less digits than its factorization.

97666561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36610.

The product of its digits is 408240, while the sum is 46.

The square root of 97666561 is about 9882.6393741753. The cubic root of 97666561 is about 460.5201441405.

The spelling of 97666561 in words is "ninety-seven million, six hundred sixty-six thousand, five hundred sixty-one".