61909056661 has 4 divisors (see below), whose sum is σ = 61933616524. Its totient is φ = 61884496800.

The previous prime is 61909056593. The next prime is 61909056679. The reversal of 61909056661 is 16665090916.

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 845704561 + 61063352100 = 29081^2 + 247110^2 .

It is a cyclic number.

It is not a de Polignac number, because 61909056661 - 2⁹ = 61909056149 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 (61909056361) 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 in 3 ways as a sum of consecutive naturals, for example, 12276150 + ... + 12281191.

It is an arithmetic number, because the mean of its divisors is an integer number (15483404131).

Almost surely, 2^61909056661 is an apocalyptic number.

It is an amenable number.

61909056661 is a deficient number, since it is larger than the sum of its proper divisors (24559863).

61909056661 is a wasteful number, since it uses less digits than its factorization.

61909056661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24559862.

The product of its (nonzero) digits is 524880, while the sum is 49.

The spelling of 61909056661 in words is "sixty-one billion, nine hundred nine million, fifty-six thousand, six hundred sixty-one".