21020230 has 32 divisors (see below), whose sum is σ = 47174400. Its totient is φ = 6551520.

The previous prime is 21020227. The next prime is 21020231. The reversal of 21020230 is 3202012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020231) 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 15 ways as a sum of consecutive naturals, for example, 12880 + ... + 14419.

It is an arithmetic number, because the mean of its divisors is an integer number (1474200).

Almost surely, 2^21020230 is an apocalyptic number.

21020230 is an abundant number, since it is smaller than the sum of its proper divisors (26154170).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21020230 is a wasteful number, since it uses less digits than its factorization.

21020230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27324.

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 21020230 is about 4584.7824375863. The cubic root of 21020230 is about 275.9809813262.

Adding to 21020230 its reverse (3202012), we get a palindrome (24222242).

The spelling of 21020230 in words is "twenty-one million, twenty thousand, two hundred thirty".