243219945091 has 2 divisors, whose sum is σ = 243219945092. Its totient is φ = 243219945090.

The previous prime is 243219945077. The next prime is 243219945139. The reversal of 243219945091 is 190549912342.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243219945091 - 2⁷ = 243219944963 is a prime.

It is not a weakly prime, because it can be changed into another prime (243219945061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121609972545 + 121609972546.

It is an arithmetic number, because the mean of its divisors is an integer number (121609972546).

Almost surely, 2^243219945091 is an apocalyptic number.

243219945091 is a deficient number, since it is larger than the sum of its proper divisors (1).

243219945091 is an equidigital number, since it uses as much as digits as its factorization.

243219945091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 699840, while the sum is 49.

The spelling of 243219945091 in words is "two hundred forty-three billion, two hundred nineteen million, nine hundred forty-five thousand, ninety-one".