166220072 has 16 divisors (see below), whose sum is σ = 312730740. Its totient is φ = 82825216.

The previous prime is 166220071. The next prime is 166220077. The reversal of 166220072 is 270022661.

It can be written as a sum of positive squares in 2 ways, for example, as 152127556 + 14092516 = 12334^2 + 3754^2 .

It is a super-2 number, since 2×166220072² = 55258224671370368, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (166220071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33113 + ... + 37800.

Almost surely, 2^166220072 is an apocalyptic number.

It is an amenable number.

166220072 is a deficient number, since it is larger than the sum of its proper divisors (146510668).

166220072 is a wasteful number, since it uses less digits than its factorization.

166220072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71212 (or 71208 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 166220072 is about 12892.6363479313. The cubic root of 166220072 is about 549.8292274221.

The spelling of 166220072 in words is "one hundred sixty-six million, two hundred twenty thousand, seventy-two".