243561782551 has 2 divisors, whose sum is σ = 243561782552. Its totient is φ = 243561782550.

The previous prime is 243561782533. The next prime is 243561782579. The reversal of 243561782551 is 155287165342.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243561782551 - 2²⁹ = 243024911639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 243561782495 and 243561782504.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243561782351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121780891275 + 121780891276.

It is an arithmetic number, because the mean of its divisors is an integer number (121780891276).

Almost surely, 2^243561782551 is an apocalyptic number.

243561782551 is a deficient number, since it is larger than the sum of its proper divisors (1).

243561782551 is an equidigital number, since it uses as much as digits as its factorization.

243561782551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016000, while the sum is 49.

The spelling of 243561782551 in words is "two hundred forty-three billion, five hundred sixty-one million, seven hundred eighty-two thousand, five hundred fifty-one".