10661755561 has 4 divisors (see below), whose sum is σ = 10888601472. Its totient is φ = 10434909652.

The previous prime is 10661755553. The next prime is 10661755567. The reversal of 10661755561 is 16555716601.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16555716601 = 14779 ⋅1120219.

It is a cyclic number.

It is not a de Polignac number, because 10661755561 - 2³ = 10661755553 is a prime.

It is a super-2 number, since 2×10661755561² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10661755567) 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, 113422885 + ... + 113422978.

It is an arithmetic number, because the mean of its divisors is an integer number (2722150368).

Almost surely, 2^10661755561 is an apocalyptic number.

It is an amenable number.

10661755561 is a deficient number, since it is larger than the sum of its proper divisors (226845911).

10661755561 is an equidigital number, since it uses as much as digits as its factorization.

10661755561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226845910.

The product of its (nonzero) digits is 189000, while the sum is 43.

The spelling of 10661755561 in words is "ten billion, six hundred sixty-one million, seven hundred fifty-five thousand, five hundred sixty-one".