261421763 has 2 divisors, whose sum is σ = 261421764. Its totient is φ = 261421762.

The previous prime is 261421711. The next prime is 261421793. The reversal of 261421763 is 367124162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261421763 - 2¹⁰ = 261420739 is a prime.

It is not a weakly prime, because it can be changed into another prime (261421793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130710881 + 130710882.

It is an arithmetic number, because the mean of its divisors is an integer number (130710882).

Almost surely, 2^261421763 is an apocalyptic number.

261421763 is a deficient number, since it is larger than the sum of its proper divisors (1).

261421763 is an equidigital number, since it uses as much as digits as its factorization.

261421763 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 32.

The square root of 261421763 is about 16168.5423894673. The cubic root of 261421763 is about 639.4117014166.

The spelling of 261421763 in words is "two hundred sixty-one million, four hundred twenty-one thousand, seven hundred sixty-three".