822021021 has 8 divisors (see below), whose sum is σ = 1217808960. Its totient is φ = 548013996.

The previous prime is 822021019. The next prime is 822021047. The reversal of 822021021 is 120120228.

It is a happy number.

It is not a de Polignac number, because 822021021 - 2¹ = 822021019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 822020985 and 822021003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (822021121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15222585 + ... + 15222638.

It is an arithmetic number, because the mean of its divisors is an integer number (152226120).

Almost surely, 2^822021021 is an apocalyptic number.

It is an amenable number.

822021021 is a deficient number, since it is larger than the sum of its proper divisors (395787939).

822021021 is a wasteful number, since it uses less digits than its factorization.

822021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30445232 (or 30445226 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 822021021 is about 28670.9089671046. The cubic root of 822021021 is about 936.7584971931.

Adding to 822021021 its reverse (120120228), we get a palindrome (942141249).

It can be divided in two parts, 8220 and 21021, that added together give a square (29241 = 171²).

The spelling of 822021021 in words is "eight hundred twenty-two million, twenty-one thousand, twenty-one".