306222021 has 18 divisors (see below), whose sum is σ = 514537062. Its totient is φ = 174983760.

The previous prime is 306221957. The next prime is 306222029. The reversal of 306222021 is 120222603.

306222021 is a `hidden beast` number, since 3 + 0 + 622 + 20 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 191517921 + 114704100 = 13839^2 + 10710^2 .

It is not a de Polignac number, because 306222021 - 2⁶ = 306221957 is a prime.

It is a super-2 number, since 2×306222021² = 187543852290648882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 306221985 and 306222003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (306222029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 346750 + ... + 347631.

Almost surely, 2^306222021 is an apocalyptic number.

It is an amenable number.

306222021 is a deficient number, since it is larger than the sum of its proper divisors (208315041).

306222021 is a wasteful number, since it uses less digits than its factorization.

306222021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694401 (or 694391 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 306222021 is about 17499.2005817409. The cubic root of 306222021 is about 674.0293472533.

Adding to 306222021 its reverse (120222603), we get a palindrome (426444624).

The spelling of 306222021 in words is "three hundred six million, two hundred twenty-two thousand, twenty-one".