21030231 has 8 divisors (see below), whose sum is σ = 28312960. Its totient is φ = 13883832.

The previous prime is 21030227. The next prime is 21030239. The reversal of 21030231 is 13203012.

It is a happy number.

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

It is not a de Polignac number, because 21030231 - 2² = 21030227 is a prime.

It is a super-2 number, since 2×21030231² = 884541231826722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030239) 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, 33721 + ... + 34338.

It is an arithmetic number, because the mean of its divisors is an integer number (3539120).

Almost surely, 2^21030231 is an apocalyptic number.

21030231 is a deficient number, since it is larger than the sum of its proper divisors (7282729).

21030231 is a wasteful number, since it uses less digits than its factorization.

21030231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68165.

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 21030231 is about 4585.8729812327. The cubic root of 21030231 is about 276.0247431084.

Adding to 21030231 its reverse (13203012), we get a palindrome (34233243).

The spelling of 21030231 in words is "twenty-one million, thirty thousand, two hundred thirty-one".