243939381 has 32 divisors (see below), whose sum is σ = 382427136. Its totient is φ = 135408000.

The previous prime is 243939379. The next prime is 243939391. The reversal of 243939381 is 183939342.

It is not a de Polignac number, because 243939381 - 2¹ = 243939379 is a prime.

It is a super-2 number, since 2×243939381² = 119012843205326322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243939331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 267316 + ... + 268226.

It is an arithmetic number, because the mean of its divisors is an integer number (11950848).

Almost surely, 2^243939381 is an apocalyptic number.

243939381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

243939381 is a deficient number, since it is larger than the sum of its proper divisors (138487755).

243939381 is a wasteful number, since it uses less digits than its factorization.

243939381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1273.

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

The square root of 243939381 is about 15618.5588643767. The cubic root of 243939381 is about 624.8282245801.

The spelling of 243939381 in words is "two hundred forty-three million, nine hundred thirty-nine thousand, three hundred eighty-one".