101661605661 has 32 divisors (see below), whose sum is σ = 174823372800. Its totient is φ = 50990143680.

The previous prime is 101661605609. The next prime is 101661605677. The reversal of 101661605661 is 166506166101.

It is not a de Polignac number, because 101661605661 - 2¹⁰ = 101661604637 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101661605861) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7581121 + ... + 7594518.

It is an arithmetic number, because the mean of its divisors is an integer number (5463230400).

Almost surely, 2^101661605661 is an apocalyptic number.

101661605661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

101661605661 is a deficient number, since it is larger than the sum of its proper divisors (73161767139).

101661605661 is a wasteful number, since it uses less digits than its factorization.

101661605661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15175689.

The product of its (nonzero) digits is 38880, while the sum is 39.

The spelling of 101661605661 in words is "one hundred one billion, six hundred sixty-one million, six hundred five thousand, six hundred sixty-one".