10663621525561 has 4 divisors (see below), whose sum is σ = 10663648678900. Its totient is φ = 10663594372224.

The previous prime is 10663621525559. The next prime is 10663621525589. The reversal of 10663621525561 is 16552512636601.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8924767879225 + 1738853646336 = 2987435^2 + 1318656^2 .

It is a cyclic number.

It is not a de Polignac number, because 10663621525561 - 2¹ = 10663621525559 is a prime.

It is a super-2 number, since 2×10663621525561² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10663621523561) 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, 12978816 + ... + 13775953.

It is an arithmetic number, because the mean of its divisors is an integer number (2665912169725).

Almost surely, 2^{10663621525561} is an apocalyptic number.

It is an amenable number.

10663621525561 is a deficient number, since it is larger than the sum of its proper divisors (27153339).

10663621525561 is an equidigital number, since it uses as much as digits as its factorization.

10663621525561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27153338.

The product of its (nonzero) digits is 1944000, while the sum is 49.

The spelling of 10663621525561 in words is "ten trillion, six hundred sixty-three billion, six hundred twenty-one million, five hundred twenty-five thousand, five hundred sixty-one".