11621475661 has 2 divisors, whose sum is σ = 11621475662. Its totient is φ = 11621475660.

The previous prime is 11621475659. The next prime is 11621475709. The reversal of 11621475661 is 16657412611.

11621475661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10267971561 + 1353504100 = 101331^2 + 36790^2 .

It is a cyclic number.

It is not a de Polignac number, because 11621475661 - 2¹ = 11621475659 is a prime.

Together with 11621475659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11621475361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5810737830 + 5810737831.

It is an arithmetic number, because the mean of its divisors is an integer number (5810737831).

Almost surely, 2^11621475661 is an apocalyptic number.

It is an amenable number.

11621475661 is a deficient number, since it is larger than the sum of its proper divisors (1).

11621475661 is an equidigital number, since it uses as much as digits as its factorization.

11621475661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 40.

The spelling of 11621475661 in words is "eleven billion, six hundred twenty-one million, four hundred seventy-five thousand, six hundred sixty-one".