66651371 has 2 divisors, whose sum is σ = 66651372. Its totient is φ = 66651370.

The previous prime is 66651341. The next prime is 66651383. The reversal of 66651371 is 17315666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66651371 is a prime.

It is not a weakly prime, because it can be changed into another prime (66651331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33325685 + 33325686.

It is an arithmetic number, because the mean of its divisors is an integer number (33325686).

Almost surely, 2^66651371 is an apocalyptic number.

66651371 is a deficient number, since it is larger than the sum of its proper divisors (1).

66651371 is an equidigital number, since it uses as much as digits as its factorization.

66651371 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22680, while the sum is 35.

The square root of 66651371 is about 8164.0290910800. The cubic root of 66651371 is about 405.4491202215.

The spelling of 66651371 in words is "sixty-six million, six hundred fifty-one thousand, three hundred seventy-one".