821222811 has 12 divisors (see below), whose sum is σ = 1197728688. Its totient is φ = 542165904.

The previous prime is 821222789. The next prime is 821222827. The reversal of 821222811 is 118222128.

It is not a de Polignac number, because 821222811 - 2⁶ = 821222747 is a prime.

It is not an unprimeable number, because it can be changed into a prime (821221811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 442020 + ... + 443873.

It is an arithmetic number, because the mean of its divisors is an integer number (99810724).

Almost surely, 2^821222811 is an apocalyptic number.

821222811 is a deficient number, since it is larger than the sum of its proper divisors (376505877).

821222811 is a wasteful number, since it uses less digits than its factorization.

821222811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 886002 (or 885999 counting only the distinct ones).

The product of its digits is 1024, while the sum is 27.

The square root of 821222811 is about 28656.9853787868. The cubic root of 821222811 is about 936.4551910184.

Adding to 821222811 its reverse (118222128), we get a palindrome (939444939).

The spelling of 821222811 in words is "eight hundred twenty-one million, two hundred twenty-two thousand, eight hundred eleven".