243991293 has 64 divisors (see below), whose sum is σ = 446423040. Its totient is φ = 114711552.

The previous prime is 243991289. The next prime is 243991301. The reversal of 243991293 is 392199342.

It is not a de Polignac number, because 243991293 - 2² = 243991289 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243991243) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 86796 + ... + 89562.

It is an arithmetic number, because the mean of its divisors is an integer number (6975360).

Almost surely, 2^243991293 is an apocalyptic number.

It is an amenable number.

243991293 is a deficient number, since it is larger than the sum of its proper divisors (202431747).

243991293 is a wasteful number, since it uses less digits than its factorization.

243991293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2826.

The product of its digits is 104976, while the sum is 42.

The square root of 243991293 is about 15620.2206450485. The cubic root of 243991293 is about 624.8725440364.

The spelling of 243991293 in words is "two hundred forty-three million, nine hundred ninety-one thousand, two hundred ninety-three".