10661603052221 has 4 divisors (see below), whose sum is σ = 11630839693344. Its totient is φ = 9692366411100.

The previous prime is 10661603052197. The next prime is 10661603052259. The reversal of 10661603052221 is 12225030616601.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 10661603052221 - 2¹⁸ = 10661602790077 is a prime.

It is a super-2 number, since 2×10661603052221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10661603252221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 484618320545 + ... + 484618320566.

It is an arithmetic number, because the mean of its divisors is an integer number (2907709923336).

Almost surely, 2^{10661603052221} is an apocalyptic number.

10661603052221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

10661603052221 is a deficient number, since it is larger than the sum of its proper divisors (969236641123).

10661603052221 is an equidigital number, since it uses as much as digits as its factorization.

10661603052221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 969236641122.

The product of its (nonzero) digits is 25920, while the sum is 35.

Adding to 10661603052221 its reverse (12225030616601), we get a palindrome (22886633668822).

The spelling of 10661603052221 in words is "ten trillion, six hundred sixty-one billion, six hundred three million, fifty-two thousand, two hundred twenty-one".