243791957 has 2 divisors, whose sum is σ = 243791958. Its totient is φ = 243791956.

The previous prime is 243791887. The next prime is 243791971. The reversal of 243791957 is 759197342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 233203441 + 10588516 = 15271^2 + 3254^2 .

It is a cyclic number.

It is not a de Polignac number, because 243791957 - 2¹² = 243787861 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243791987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121895978 + 121895979.

It is an arithmetic number, because the mean of its divisors is an integer number (121895979).

Almost surely, 2^243791957 is an apocalyptic number.

It is an amenable number.

243791957 is a deficient number, since it is larger than the sum of its proper divisors (1).

243791957 is an equidigital number, since it uses as much as digits as its factorization.

243791957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 476280, while the sum is 47.

The square root of 243791957 is about 15613.8386375676. The cubic root of 243791957 is about 624.7023282223.

The spelling of 243791957 in words is "two hundred forty-three million, seven hundred ninety-one thousand, nine hundred fifty-seven".