66705651 has 6 divisors (see below), whose sum is σ = 96352620. Its totient is φ = 44470428.

The previous prime is 66705629. The next prime is 66705659. The reversal of 66705651 is 15650766.

It is a happy number.

It is not a de Polignac number, because 66705651 - 2¹¹ = 66703603 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66705659) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3705861 + ... + 3705878.

It is an arithmetic number, because the mean of its divisors is an integer number (16058770).

Almost surely, 2^66705651 is an apocalyptic number.

66705651 is a deficient number, since it is larger than the sum of its proper divisors (29646969).

66705651 is a wasteful number, since it uses less digits than its factorization.

66705651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7411745 (or 7411742 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The square root of 66705651 is about 8167.3527534936. The cubic root of 66705651 is about 405.5591545006.

It can be divided in two parts, 6670 and 5651, that added together give a palindrome (12321).

The spelling of 66705651 in words is "sixty-six million, seven hundred five thousand, six hundred fifty-one".