11620605661 has 4 divisors (see below), whose sum is σ = 13280692192. Its totient is φ = 9960519132.

The previous prime is 11620605653. The next prime is 11620605673. The reversal of 11620605661 is 16650602611.

It is a happy number.

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: 16650602611 = 1301 ⋅12798311.

It is a cyclic number.

It is not a de Polignac number, because 11620605661 - 2³ = 11620605653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11620605611) by changing a digit.

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, 830043255 + ... + 830043268.

It is an arithmetic number, because the mean of its divisors is an integer number (3320173048).

Almost surely, 2^11620605661 is an apocalyptic number.

It is an amenable number.

11620605661 is a deficient number, since it is larger than the sum of its proper divisors (1660086531).

11620605661 is an equidigital number, since it uses as much as digits as its factorization.

11620605661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1660086530.

The product of its (nonzero) digits is 12960, while the sum is 34.

The spelling of 11620605661 in words is "eleven billion, six hundred twenty million, six hundred five thousand, six hundred sixty-one".