263811421 has 2 divisors, whose sum is σ = 263811422. Its totient is φ = 263811420.

The previous prime is 263811419. The next prime is 263811461. The reversal of 263811421 is 124118362.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 263575225 + 236196 = 16235^2 + 486^2 .

It is a cyclic number.

It is not a de Polignac number, because 263811421 - 2¹ = 263811419 is a prime.

Together with 263811419, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 263811421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (263811461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 131905710 + 131905711.

It is an arithmetic number, because the mean of its divisors is an integer number (131905711).

Almost surely, 2^263811421 is an apocalyptic number.

It is an amenable number.

263811421 is a deficient number, since it is larger than the sum of its proper divisors (1).

263811421 is an equidigital number, since it uses as much as digits as its factorization.

263811421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 28.

The square root of 263811421 is about 16242.2726550197. The cubic root of 263811421 is about 641.3540837525.

Adding to 263811421 its reverse (124118362), we get a palindrome (387929783).

The spelling of 263811421 in words is "two hundred sixty-three million, eight hundred eleven thousand, four hundred twenty-one".