66207621 has 16 divisors (see below), whose sum is σ = 89547840. Its totient is φ = 43507200.

The previous prime is 66207601. The next prime is 66207629. The reversal of 66207621 is 12670266.

It is not a de Polignac number, because 66207621 - 2⁹ = 66207109 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66207629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106650 + ... + 107268.

It is an arithmetic number, because the mean of its divisors is an integer number (5596740).

Almost surely, 2^66207621 is an apocalyptic number.

It is an amenable number.

66207621 is a deficient number, since it is larger than the sum of its proper divisors (23340219).

66207621 is a wasteful number, since it uses less digits than its factorization.

66207621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1076.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 66207621 is about 8136.8065603159. The cubic root of 66207621 is about 404.5473192402.

Adding to 66207621 its reverse (12670266), we get a palindrome (78877887).

It can be divided in two parts, 6620 and 7621, that added together give a palindrome (14241).

The spelling of 66207621 in words is "sixty-six million, two hundred seven thousand, six hundred twenty-one".