247421543561 has 2 divisors, whose sum is σ = 247421543562. Its totient is φ = 247421543560.

The previous prime is 247421543521. The next prime is 247421543597. The reversal of 247421543561 is 165345124742.

247421543561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 193947756025 + 53473787536 = 440395^2 + 231244^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-247421543561 is a prime.

It is a super-2 number, since 2×247421543561² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (247421543521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123710771780 + 123710771781.

It is an arithmetic number, because the mean of its divisors is an integer number (123710771781).

Almost surely, 2^247421543561 is an apocalyptic number.

It is an amenable number.

247421543561 is a deficient number, since it is larger than the sum of its proper divisors (1).

247421543561 is an equidigital number, since it uses as much as digits as its factorization.

247421543561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 806400, while the sum is 44.

The spelling of 247421543561 in words is "two hundred forty-seven billion, four hundred twenty-one million, five hundred forty-three thousand, five hundred sixty-one".