265403821 has 2 divisors, whose sum is σ = 265403822. Its totient is φ = 265403820.

The previous prime is 265403819. The next prime is 265403851. The reversal of 265403821 is 128304562.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 263412900 + 1990921 = 16230^2 + 1411^2 .

It is a cyclic number.

It is not a de Polignac number, because 265403821 - 2¹ = 265403819 is a prime.

Together with 265403819, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (265403851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132701910 + 132701911.

It is an arithmetic number, because the mean of its divisors is an integer number (132701911).

Almost surely, 2^265403821 is an apocalyptic number.

It is an amenable number.

265403821 is a deficient number, since it is larger than the sum of its proper divisors (1).

265403821 is an equidigital number, since it uses as much as digits as its factorization.

265403821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 265403821 is about 16291.2191379283. The cubic root of 265403821 is about 642.6419282010.

The spelling of 265403821 in words is "two hundred sixty-five million, four hundred three thousand, eight hundred twenty-one".