15666610505601 has 48 divisors (see below), whose sum is σ = 23987342594880. Its totient is φ = 9076736592000.

The previous prime is 15666610505561. The next prime is 15666610505621. The reversal of 15666610505601 is 10650501666651.

It is not a de Polignac number, because 15666610505601 - 2⁹ = 15666610505089 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (15666610505621) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6304255 + ... + 8430708.

It is an arithmetic number, because the mean of its divisors is an integer number (499736304060).

Almost surely, 2^{15666610505601} is an apocalyptic number.

15666610505601 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15666610505601 is a deficient number, since it is larger than the sum of its proper divisors (8320732089279).

15666610505601 is a wasteful number, since it uses less digits than its factorization.

15666610505601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14735118 (or 14735107 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 48.

It can be divided in two parts, 1566661050 and 5601, that added together give a palindrome (1566666651).

The spelling of 15666610505601 in words is "fifteen trillion, six hundred sixty-six billion, six hundred ten million, five hundred five thousand, six hundred one".