263621 has 2 divisors, whose sum is σ = 263622. Its totient is φ = 263620.

The previous prime is 263611. The next prime is 263647. The reversal of 263621 is 126362.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 261121 + 2500 = 511^2 + 50^2 .

It is a cyclic number.

It is not a de Polignac number, because 263621 - 2¹⁰ = 262597 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 263593 and 263602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (263611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 131810 + 131811.

It is an arithmetic number, because the mean of its divisors is an integer number (131811).

2²⁶³⁶²¹ is an apocalyptic number.

It is an amenable number.

263621 is a deficient number, since it is larger than the sum of its proper divisors (1).

263621 is an equidigital number, since it uses as much as digits as its factorization.

263621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 20.

The square root of 263621 is about 513.4403568089. The cubic root of 263621 is about 64.1199735264.

Adding to 263621 its reverse (126362), we get a palindrome (389983).

The spelling of 263621 in words is "two hundred sixty-three thousand, six hundred twenty-one".