20661111165650 has 12 divisors (see below), whose sum is σ = 38429666768202. Its totient is φ = 8264444466240.

The previous prime is 20661111165637. The next prime is 20661111165713. The reversal of 20661111165650 is 5656111116602.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 8947474860289 + 11713636305361 = 2991233^2 + 3422519^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20661111165598 and 20661111165607.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 206611111607 + ... + 206611111706.

Almost surely, 2^{20661111165650} is an apocalyptic number.

20661111165650 is a deficient number, since it is larger than the sum of its proper divisors (17768555602552).

20661111165650 is a wasteful number, since it uses less digits than its factorization.

20661111165650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413222223325 (or 413222223320 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 41.

The spelling of 20661111165650 in words is "twenty trillion, six hundred sixty-one billion, one hundred eleven million, one hundred sixty-five thousand, six hundred fifty".