67869561521 has 2 divisors, whose sum is σ = 67869561522. Its totient is φ = 67869561520.

The previous prime is 67869561451. The next prime is 67869561541. The reversal of 67869561521 is 12516596876.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56007955600 + 11861605921 = 236660^2 + 108911^2 .

It is a cyclic number.

It is not a de Polignac number, because 67869561521 - 2¹⁰ = 67869560497 is a prime.

It is not a weakly prime, because it can be changed into another prime (67869561541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33934780760 + 33934780761.

It is an arithmetic number, because the mean of its divisors is an integer number (33934780761).

Almost surely, 2^67869561521 is an apocalyptic number.

It is an amenable number.

67869561521 is a deficient number, since it is larger than the sum of its proper divisors (1).

67869561521 is an equidigital number, since it uses as much as digits as its factorization.

67869561521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5443200, while the sum is 56.

The spelling of 67869561521 in words is "sixty-seven billion, eight hundred sixty-nine million, five hundred sixty-one thousand, five hundred twenty-one".