247561217389 has 2 divisors, whose sum is σ = 247561217390. Its totient is φ = 247561217388.

The previous prime is 247561217297. The next prime is 247561217399. The reversal of 247561217389 is 983712165742.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 231858621289 + 15702596100 = 481517^2 + 125310^2 .

It is a cyclic number.

It is not a de Polignac number, because 247561217389 - 2¹⁵ = 247561184621 is a prime.

It is a super-2 number, since 2×247561217389² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247561217399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123780608694 + 123780608695.

It is an arithmetic number, because the mean of its divisors is an integer number (123780608695).

Almost surely, 2^247561217389 is an apocalyptic number.

It is an amenable number.

247561217389 is a deficient number, since it is larger than the sum of its proper divisors (1).

247561217389 is an equidigital number, since it uses as much as digits as its factorization.

247561217389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5080320, while the sum is 55.

The spelling of 247561217389 in words is "two hundred forty-seven billion, five hundred sixty-one million, two hundred seventeen thousand, three hundred eighty-nine".