66687212 has 24 divisors (see below), whose sum is σ = 122551296. Its totient is φ = 31691088.

The previous prime is 66687199. The next prime is 66687217. The reversal of 66687212 is 21278666.

It is a happy number.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (66687217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12773 + ... + 17219.

It is an arithmetic number, because the mean of its divisors is an integer number (5106304).

Almost surely, 2^66687212 is an apocalyptic number.

It is an amenable number.

66687212 is a deficient number, since it is larger than the sum of its proper divisors (55864084).

66687212 is a wasteful number, since it uses less digits than its factorization.

66687212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4637 (or 4635 counting only the distinct ones).

The product of its digits is 48384, while the sum is 38.

The square root of 66687212 is about 8166.2238519404. The cubic root of 66687212 is about 405.5217823825.

It can be divided in two parts, 666 and 87212, that added together give a palindrome (87878).

The spelling of 66687212 in words is "sixty-six million, six hundred eighty-seven thousand, two hundred twelve".