66610897 has 4 divisors (see below), whose sum is σ = 67058100. Its totient is φ = 66163696.

The previous prime is 66610889. The next prime is 66610919. The reversal of 66610897 is 79801666.

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 6765201 + 59845696 = 2601^2 + 7736^2 .

It is a cyclic number.

It is not a de Polignac number, because 66610897 - 2³ = 66610889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66610807) 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, 223378 + ... + 223675.

It is an arithmetic number, because the mean of its divisors is an integer number (16764525).

Almost surely, 2^66610897 is an apocalyptic number.

It is an amenable number.

66610897 is a deficient number, since it is larger than the sum of its proper divisors (447203).

66610897 is a wasteful number, since it uses less digits than its factorization.

66610897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447202.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 66610897 is about 8161.5499140788. The cubic root of 66610897 is about 405.3670340356.

The spelling of 66610897 in words is "sixty-six million, six hundred ten thousand, eight hundred ninety-seven".