21030331 has 8 divisors (see below), whose sum is σ = 24101120. Its totient is φ = 17976168.

The previous prime is 21030329. The next prime is 21030337. The reversal of 21030331 is 13303012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21030331 - 2¹ = 21030329 is a prime.

It is a super-2 number, since 2×21030331² = 884549643939122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21030337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1311 + ... + 6616.

It is an arithmetic number, because the mean of its divisors is an integer number (3012640).

Almost surely, 2^21030331 is an apocalyptic number.

21030331 is a deficient number, since it is larger than the sum of its proper divisors (3070789).

21030331 is an equidigital number, since it uses as much as digits as its factorization.

21030331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8313.

The product of its (nonzero) digits is 54, while the sum is 13.

The square root of 21030331 is about 4585.8838842692. The cubic root of 21030331 is about 276.0251806124.

Adding to 21030331 its reverse (13303012), we get a palindrome (34333343).

The spelling of 21030331 in words is "twenty-one million, thirty thousand, three hundred thirty-one".