10551666661 has 4 divisors (see below), whose sum is σ = 10552115500. Its totient is φ = 10551217824.

The previous prime is 10551666557. The next prime is 10551666673. The reversal of 10551666661 is 16666615501.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16666615501 = 115783 ⋅143947.

It can be written as a sum of positive squares in 2 ways, for example, as 2394144900 + 8157521761 = 48930^2 + 90319^2 .

It is a cyclic number.

It is not a de Polignac number, because 10551666661 - 2⁷ = 10551666533 is a prime.

It is a super-2 number, since 2×10551666661² (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 (10551666061) 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, 187086 + ... + 236863.

It is an arithmetic number, because the mean of its divisors is an integer number (2638028875).

Almost surely, 2^10551666661 is an apocalyptic number.

It is an amenable number.

10551666661 is a deficient number, since it is larger than the sum of its proper divisors (448839).

10551666661 is an equidigital number, since it uses as much as digits as its factorization.

10551666661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448838.

The product of its (nonzero) digits is 194400, while the sum is 43.

The spelling of 10551666661 in words is "ten billion, five hundred fifty-one million, six hundred sixty-six thousand, six hundred sixty-one".