261421121434279 has 2 divisors, whose sum is σ = 261421121434280. Its totient is φ = 261421121434278.

The previous prime is 261421121434201. The next prime is 261421121434289. The reversal of 261421121434279 is 972434121124162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261421121434279 - 2¹¹ = 261421121432231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261421121434289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130710560717139 + 130710560717140.

It is an arithmetic number, because the mean of its divisors is an integer number (130710560717140).

Almost surely, 2^{261421121434279} is an apocalyptic number.

261421121434279 is a deficient number, since it is larger than the sum of its proper divisors (1).

261421121434279 is an equidigital number, since it uses as much as digits as its factorization.

261421121434279 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1161216, while the sum is 49.

The spelling of 261421121434279 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, one hundred twenty-one million, four hundred thirty-four thousand, two hundred seventy-nine".