642264281 has 2 divisors, whose sum is σ = 642264282. Its totient is φ = 642264280.

The previous prime is 642264269. The next prime is 642264319. The reversal of 642264281 is 182462246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 470890000 + 171374281 = 21700^2 + 13091^2 .

It is a cyclic number.

It is not a de Polignac number, because 642264281 - 2¹⁴ = 642247897 is a prime.

It is a super-2 number, since 2×642264281² = 825006813296893922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (642266281) 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, 321132140 + 321132141.

It is an arithmetic number, because the mean of its divisors is an integer number (321132141).

Almost surely, 2^642264281 is an apocalyptic number.

It is an amenable number.

642264281 is a deficient number, since it is larger than the sum of its proper divisors (1).

642264281 is an equidigital number, since it uses as much as digits as its factorization.

642264281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36864, while the sum is 35.

The square root of 642264281 is about 25342.9335515840. The cubic root of 642264281 is about 862.7889809788.

The spelling of 642264281 in words is "six hundred forty-two million, two hundred sixty-four thousand, two hundred eighty-one".