30221021 has 4 divisors (see below), whose sum is σ = 30299100. Its totient is φ = 30142944.

The previous prime is 30221003. The next prime is 30221033. The reversal of 30221021 is 12012203.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13980121 + 16240900 = 3739^2 + 4030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30221021 is a prime.

It is a super-2 number, since 2×30221021² = 1826620220564882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 30220993 and 30221011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30221041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38456 + ... + 39233.

It is an arithmetic number, because the mean of its divisors is an integer number (7574775).

Almost surely, 2^30221021 is an apocalyptic number.

It is an amenable number.

30221021 is a deficient number, since it is larger than the sum of its proper divisors (78079).

30221021 is an equidigital number, since it uses as much as digits as its factorization.

30221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78078.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 30221021 is about 5497.3649142112. The cubic root of 30221021 is about 311.4844549937.

Adding to 30221021 its reverse (12012203), we get a palindrome (42233224).

The spelling of 30221021 in words is "thirty million, two hundred twenty-one thousand, twenty-one".