91061610661 has 16 divisors (see below), whose sum is σ = 110201831424. Its totient is φ = 73455047424.

The previous prime is 91061610617. The next prime is 91061610667. The reversal of 91061610661 is 16601616019.

It is a cyclic number.

It is not a de Polignac number, because 91061610661 - 2¹⁹ = 91061086373 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91061610661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91061610667) 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 15 ways as a sum of consecutive naturals, for example, 1717596 + ... + 1769818.

It is an arithmetic number, because the mean of its divisors is an integer number (6887614464).

Almost surely, 2^91061610661 is an apocalyptic number.

It is an amenable number.

91061610661 is a deficient number, since it is larger than the sum of its proper divisors (19140220763).

91061610661 is a wasteful number, since it uses less digits than its factorization.

91061610661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66900.

The product of its (nonzero) digits is 11664, while the sum is 37.

The spelling of 91061610661 in words is "ninety-one billion, sixty-one million, six hundred ten thousand, six hundred sixty-one".