166051661561505 has 48 divisors (see below), whose sum is σ = 298503069131904. Its totient is φ = 88554927646080.

The previous prime is 166051661561503. The next prime is 166051661561521. The reversal of 166051661561505 is 505165166150661.

166051661561505 is a `hidden beast` number, since 1 + 6 + 6 + 0 + 5 + 1 + 6 + 6 + 15 + 615 + 0 + 5 = 666.

166051661561505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 166051661561505 - 2¹ = 166051661561503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166051661561503) 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, 13497525 + ... + 22677885.

It is an arithmetic number, because the mean of its divisors is an integer number (6218813940248).

Almost surely, 2^{166051661561505} is an apocalyptic number.

166051661561505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

166051661561505 is a deficient number, since it is larger than the sum of its proper divisors (132451407570399).

166051661561505 is an equidigital number, since it uses as much as digits as its factorization.

166051661561505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9195268 (or 9195256 counting only the distinct ones).

The product of its (nonzero) digits is 4860000, while the sum is 54.

The spelling of 166051661561505 in words is "one hundred sixty-six trillion, fifty-one billion, six hundred sixty-one million, five hundred sixty-one thousand, five hundred five".