166121566 has 32 divisors (see below), whose sum is σ = 273103488. Its totient is φ = 75327840.

The previous prime is 166121561. The next prime is 166121597. The reversal of 166121566 is 665121661.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166121561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 586861 + ... + 587143.

It is an arithmetic number, because the mean of its divisors is an integer number (8534484).

Almost surely, 2^166121566 is an apocalyptic number.

166121566 is a deficient number, since it is larger than the sum of its proper divisors (106981922).

166121566 is a wasteful number, since it uses less digits than its factorization.

166121566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616.

The product of its digits is 12960, while the sum is 34.

The square root of 166121566 is about 12888.8155390633. The cubic root of 166121566 is about 549.7205919650.

The spelling of 166121566 in words is "one hundred sixty-six million, one hundred twenty-one thousand, five hundred sixty-six".