166561110 has 80 divisors (see below), whose sum is σ = 455341392. Its totient is φ = 43675200.

The previous prime is 166561103. The next prime is 166561117. The reversal of 166561110 is 11165661.

166561110 is a `hidden beast` number, since 1 + 6 + 656 + 1 + 1 + 1 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (166561103) and next prime (166561117).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166561117) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 47725 + ... + 51095.

Almost surely, 2^166561110 is an apocalyptic number.

166561110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 166561110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227670696).

166561110 is an abundant number, since it is smaller than the sum of its proper divisors (288780282).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166561110 is a wasteful number, since it uses less digits than its factorization.

166561110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3451 (or 3442 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 166561110 is about 12905.8556477283. The cubic root of 166561110 is about 550.2050034686.

It can be divided in two parts, 16656 and 1110, that added together give a triangular number (17766 = T₁₈₈).

The spelling of 166561110 in words is "one hundred sixty-six million, five hundred sixty-one thousand, one hundred ten".