10646221261 has 4 divisors (see below), whose sum is σ = 11465161372. Its totient is φ = 9827281152.

The previous prime is 10646221259. The next prime is 10646221277. The reversal of 10646221261 is 16212264601.

It is a happy number.

10646221261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16212264601 = 13 ⋅1247097277.

It can be written as a sum of positive squares in 2 ways, for example, as 5154522025 + 5491699236 = 71795^2 + 74106^2 .

It is not a de Polignac number, because 10646221261 - 2¹ = 10646221259 is a prime.

It is a super-2 number, since 2×10646221261² (a number of 21 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 (10646221241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 409470036 + ... + 409470061.

It is an arithmetic number, because the mean of its divisors is an integer number (2866290343).

Almost surely, 2^10646221261 is an apocalyptic number.

It is an amenable number.

10646221261 is a deficient number, since it is larger than the sum of its proper divisors (818940111).

10646221261 is an equidigital number, since it uses as much as digits as its factorization.

10646221261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 818940110.

The product of its (nonzero) digits is 6912, while the sum is 31.

Adding to 10646221261 its reverse (16212264601), we get a palindrome (26858485862).

The spelling of 10646221261 in words is "ten billion, six hundred forty-six million, two hundred twenty-one thousand, two hundred sixty-one".