1005222821 has 2 divisors, whose sum is σ = 1005222822. Its totient is φ = 1005222820.

The previous prime is 1005222811. The next prime is 1005222847. The reversal of 1005222821 is 1282225001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 543402721 + 461820100 = 23311^2 + 21490^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1005222821 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1005222811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502611410 + 502611411.

It is an arithmetic number, because the mean of its divisors is an integer number (502611411).

Almost surely, 2^1005222821 is an apocalyptic number.

It is an amenable number.

1005222821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1005222821 is an equidigital number, since it uses as much as digits as its factorization.

1005222821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 1005222821 is about 31705.2491079947. The cubic root of 1005222821 is about 1001.7379182239.

Adding to 1005222821 its reverse (1282225001), we get a palindrome (2287447822).

The spelling of 1005222821 in words is "one billion, five million, two hundred twenty-two thousand, eight hundred twenty-one".