10661026405 has 4 divisors (see below), whose sum is σ = 12793231692. Its totient is φ = 8528821120.

The previous prime is 10661026391. The next prime is 10661026423. The reversal of 10661026405 is 50462016601.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50462016601 = 241 ⋅209385961.

It can be written as a sum of positive squares in 2 ways, for example, as 2704208004 + 7956818401 = 52002^2 + 89201^2 .

It is a de Polignac number, because none of the positive numbers 2^k-10661026405 is a prime.

It is a super-2 number, since 2×10661026405² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1066102636 + ... + 1066102645.

It is an arithmetic number, because the mean of its divisors is an integer number (3198307923).

Almost surely, 2^10661026405 is an apocalyptic number.

It is an amenable number.

10661026405 is a deficient number, since it is larger than the sum of its proper divisors (2132205287).

10661026405 is an equidigital number, since it uses as much as digits as its factorization.

10661026405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2132205286.

The product of its (nonzero) digits is 8640, while the sum is 31.

The spelling of 10661026405 in words is "ten billion, six hundred sixty-one million, twenty-six thousand, four hundred five".