264256021 has 2 divisors, whose sum is σ = 264256022. Its totient is φ = 264256020.

The previous prime is 264255991. The next prime is 264256049. The reversal of 264256021 is 120652462.

It is an a-pointer prime, because the next prime (264256049) can be obtained adding 264256021 to its sum of digits (28).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 253764900 + 10491121 = 15930^2 + 3239^2 .

It is a cyclic number.

It is not a de Polignac number, because 264256021 - 2²³ = 255867413 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (264256051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132128010 + 132128011.

It is an arithmetic number, because the mean of its divisors is an integer number (132128011).

Almost surely, 2^264256021 is an apocalyptic number.

It is an amenable number.

264256021 is a deficient number, since it is larger than the sum of its proper divisors (1).

264256021 is an equidigital number, since it uses as much as digits as its factorization.

264256021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 264256021 is about 16255.9534017541. The cubic root of 264256021 is about 641.7141717645.

The spelling of 264256021 in words is "two hundred sixty-four million, two hundred fifty-six thousand, twenty-one".