166689428 has 6 divisors (see below), whose sum is σ = 291706506. Its totient is φ = 83344712.

The previous prime is 166689421. The next prime is 166689463. The reversal of 166689428 is 824986661.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 102657424 + 64032004 = 10132^2 + 8002^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166689421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20836175 + ... + 20836182.

It is an arithmetic number, because the mean of its divisors is an integer number (48617751).

Almost surely, 2^166689428 is an apocalyptic number.

It is an amenable number.

166689428 is a deficient number, since it is larger than the sum of its proper divisors (125017078).

166689428 is a wasteful number, since it uses less digits than its factorization.

166689428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41672361 (or 41672359 counting only the distinct ones).

The product of its digits is 995328, while the sum is 50.

The square root of 166689428 is about 12910.8259999119. The cubic root of 166689428 is about 550.3462590977.

The spelling of 166689428 in words is "one hundred sixty-six million, six hundred eighty-nine thousand, four hundred twenty-eight".