166261560 has 128 divisors (see below), whose sum is σ = 522547200. Its totient is φ = 42275840.

The previous prime is 166261541. The next prime is 166261567. The reversal of 166261560 is 65162661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166261567) 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, 230881 + ... + 231599.

It is an arithmetic number, because the mean of its divisors is an integer number (4082400).

Almost surely, 2^166261560 is an apocalyptic number.

166261560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166261560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261273600).

166261560 is an abundant number, since it is smaller than the sum of its proper divisors (356285640).

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

166261560 is a wasteful number, since it uses less digits than its factorization.

166261560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821 (or 817 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 166261560 is about 12894.2452280077. The cubic root of 166261560 is about 549.8749688241.

It can be divided in two parts, 166 and 261560, that added together give a triangular number (261726 = T₇₂₃).

The spelling of 166261560 in words is "one hundred sixty-six million, two hundred sixty-one thousand, five hundred sixty".