36661382221 has 4 divisors (see below), whose sum is σ = 36669770172. Its totient is φ = 36652994272.

The previous prime is 36661382209. The next prime is 36661382237. The reversal of 36661382221 is 12228316663.

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 14158382121 + 22503000100 = 118989^2 + 150010^2 .

It is a cyclic number.

It is not a de Polignac number, because 36661382221 - 2¹⁵ = 36661349453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (36661382281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4187416 + ... + 4196161.

It is an arithmetic number, because the mean of its divisors is an integer number (9167442543).

Almost surely, 2^36661382221 is an apocalyptic number.

It is an amenable number.

36661382221 is a deficient number, since it is larger than the sum of its proper divisors (8387951).

36661382221 is an equidigital number, since it uses as much as digits as its factorization.

36661382221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8387950.

The product of its digits is 124416, while the sum is 40.

Adding to 36661382221 its reverse (12228316663), we get a palindrome (48889698884).

The spelling of 36661382221 in words is "thirty-six billion, six hundred sixty-one million, three hundred eighty-two thousand, two hundred twenty-one".