243921966 has 16 divisors (see below), whose sum is σ = 489888000. Its totient is φ = 80966648.

The previous prime is 243921959. The next prime is 243921971. The reversal of 243921966 is 669129342.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83616 + ... + 86483.

It is an arithmetic number, because the mean of its divisors is an integer number (30618000).

Almost surely, 2^243921966 is an apocalyptic number.

243921966 is an abundant number, since it is smaller than the sum of its proper divisors (245966034).

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

243921966 is a wasteful number, since it uses less digits than its factorization.

243921966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170343.

The product of its digits is 139968, while the sum is 42.

The square root of 243921966 is about 15618.0013446023. The cubic root of 243921966 is about 624.8133552542.

Subtracting from 243921966 its sum of digits (42), we obtain a square (243921924 = 15618²).

The spelling of 243921966 in words is "two hundred forty-three million, nine hundred twenty-one thousand, nine hundred sixty-six".