66561301 has 4 divisors (see below), whose sum is σ = 66579372. Its totient is φ = 66543232.

The previous prime is 66561289. The next prime is 66561331. The reversal of 66561301 is 10316566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39250225 + 27311076 = 6265^2 + 5226^2 .

It is a cyclic number.

It is not a de Polignac number, because 66561301 - 2¹¹ = 66559253 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66561301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66561331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1306 + ... + 11611.

It is an arithmetic number, because the mean of its divisors is an integer number (16644843).

Almost surely, 2^66561301 is an apocalyptic number.

It is an amenable number.

66561301 is a deficient number, since it is larger than the sum of its proper divisors (18071).

66561301 is a wasteful number, since it uses less digits than its factorization.

66561301 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18070.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 66561301 is about 8158.5109548250. The cubic root of 66561301 is about 405.2664019764.

Adding to 66561301 its reverse (10316566), we get a palindrome (76877867).

The spelling of 66561301 in words is "sixty-six million, five hundred sixty-one thousand, three hundred one".