66610651 has 4 divisors (see below), whose sum is σ = 68907600. Its totient is φ = 64313704.

The previous prime is 66610639. The next prime is 66610657. The reversal of 66610651 is 15601666.

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 66610651 - 2¹¹ = 66608603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66610657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1148431 + ... + 1148488.

It is an arithmetic number, because the mean of its divisors is an integer number (17226900).

Almost surely, 2^66610651 is an apocalyptic number.

66610651 is a deficient number, since it is larger than the sum of its proper divisors (2296949).

66610651 is a wasteful number, since it uses less digits than its factorization.

66610651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2296948.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 66610651 is about 8161.5348433980. The cubic root of 66610651 is about 405.3665350161.

The spelling of 66610651 in words is "sixty-six million, six hundred ten thousand, six hundred fifty-one".