166221880 has 128 divisors (see below), whose sum is σ = 438048000. Its totient is φ = 56125440.

The previous prime is 166221877. The next prime is 166221917. The reversal of 166221880 is 88122661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 493072 + ... + 493408.

It is an arithmetic number, because the mean of its divisors is an integer number (3422250).

Almost surely, 2^166221880 is an apocalyptic number.

166221880 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 166221880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (219024000).

166221880 is an abundant number, since it is smaller than the sum of its proper divisors (271826120).

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

166221880 is a wasteful number, since it uses less digits than its factorization.

166221880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437 (or 433 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 166221880 is about 12892.7064652849. The cubic root of 166221880 is about 549.8312209392.

The spelling of 166221880 in words is "one hundred sixty-six million, two hundred twenty-one thousand, eight hundred eighty".