4243540991 has 2 divisors, whose sum is σ = 4243540992. Its totient is φ = 4243540990.

The previous prime is 4243540937. The next prime is 4243541017. The reversal of 4243540991 is 1990453424.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4243540991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4243540891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2121770495 + 2121770496.

It is an arithmetic number, because the mean of its divisors is an integer number (2121770496).

Almost surely, 2^4243540991 is an apocalyptic number.

4243540991 is a deficient number, since it is larger than the sum of its proper divisors (1).

4243540991 is an equidigital number, since it uses as much as digits as its factorization.

4243540991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 41.

The square root of 4243540991 is about 65142.4668783736. The cubic root of 4243540991 is about 1618.9849088367.

The spelling of 4243540991 in words is "four billion, two hundred forty-three million, five hundred forty thousand, nine hundred ninety-one".