661171170 has 64 divisors (see below), whose sum is σ = 1755509760. Its totient is φ = 158020800.

The previous prime is 661171163. The next prime is 661171171. The reversal of 661171170 is 71171166.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661171171) 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, 9321 + ... + 37539.

It is an arithmetic number, because the mean of its divisors is an integer number (27429840).

Almost surely, 2^661171170 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661171170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (877754880).

661171170 is an abundant number, since it is smaller than the sum of its proper divisors (1094338590).

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

661171170 is a wasteful number, since it uses less digits than its factorization.

661171170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28311.

The product of its (nonzero) digits is 1764, while the sum is 30.

The square root of 661171170 is about 25713.2489195745. The cubic root of 661171170 is about 871.1734594599.

The spelling of 661171170 in words is "six hundred sixty-one million, one hundred seventy-one thousand, one hundred seventy".