10661272561 has 8 divisors (see below), whose sum is σ = 10791666144. Its totient is φ = 10530925440.

The previous prime is 10661272541. The next prime is 10661272579. The reversal of 10661272561 is 16527216601.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 10661272561 - 2²³ = 10652883953 is a prime.

It is a super-2 number, since 2×10661272561² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 10661272561.

It is not an unprimeable number, because it can be changed into a prime (10661272511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 758881 + ... + 772801.

It is an arithmetic number, because the mean of its divisors is an integer number (1348958268).

Almost surely, 2^10661272561 is an apocalyptic number.

It is an amenable number.

10661272561 is a deficient number, since it is larger than the sum of its proper divisors (130393583).

10661272561 is an equidigital number, since it uses as much as digits as its factorization.

10661272561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23231.

The product of its (nonzero) digits is 30240, while the sum is 37.

The spelling of 10661272561 in words is "ten billion, six hundred sixty-one million, two hundred seventy-two thousand, five hundred sixty-one".