166722220 has 24 divisors (see below), whose sum is σ = 400133664. Its totient is φ = 57161856.

The previous prime is 166722217. The next prime is 166722221. The reversal of 166722220 is 22227661.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (166722221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 595297 + ... + 595576.

It is an arithmetic number, because the mean of its divisors is an integer number (16672236).

Almost surely, 2^166722220 is an apocalyptic number.

166722220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166722220 is an abundant number, since it is smaller than the sum of its proper divisors (233411444).

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

166722220 is a wasteful number, since it uses less digits than its factorization.

166722220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1190889 (or 1190887 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 166722220 is about 12912.0958794458. The cubic root of 166722220 is about 550.3823457119.

Adding to 166722220 its reverse (22227661), we get a palindrome (188949881).

The spelling of 166722220 in words is "one hundred sixty-six million, seven hundred twenty-two thousand, two hundred twenty".