261015853669 has 2 divisors, whose sum is σ = 261015853670. Its totient is φ = 261015853668.

The previous prime is 261015853667. The next prime is 261015853729. The reversal of 261015853669 is 966358510162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 242270684100 + 18745169569 = 492210^2 + 136913^2 .

It is a cyclic number.

It is not a de Polignac number, because 261015853669 - 2¹ = 261015853667 is a prime.

It is a super-2 number, since 2×261015853669² (a number of 24 digits) contains 22 as substring.

Together with 261015853667, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261015853667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130507926834 + 130507926835.

It is an arithmetic number, because the mean of its divisors is an integer number (130507926835).

Almost surely, 2^261015853669 is an apocalyptic number.

It is an amenable number.

261015853669 is a deficient number, since it is larger than the sum of its proper divisors (1).

261015853669 is an equidigital number, since it uses as much as digits as its factorization.

261015853669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2332800, while the sum is 52.

The spelling of 261015853669 in words is "two hundred sixty-one billion, fifteen million, eight hundred fifty-three thousand, six hundred sixty-nine".