66610247 has 4 divisors (see below), whose sum is σ = 72665736. Its totient is φ = 60554760.

The previous prime is 66610217. The next prime is 66610279. The reversal of 66610247 is 74201666.

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

It is a cyclic number.

It is not a de Polignac number, because 66610247 - 2¹⁰ = 66609223 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66610217) 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, 3027728 + ... + 3027749.

It is an arithmetic number, because the mean of its divisors is an integer number (18166434).

Almost surely, 2^66610247 is an apocalyptic number.

66610247 is a deficient number, since it is larger than the sum of its proper divisors (6055489).

66610247 is a wasteful number, since it uses less digits than its factorization.

66610247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6055488.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 66610247 is about 8161.5100931139. The cubic root of 66610247 is about 405.3657154854.

The spelling of 66610247 in words is "sixty-six million, six hundred ten thousand, two hundred forty-seven".