21001230 has 24 divisors (see below), whose sum is σ = 54603432. Its totient is φ = 5600304.

The previous prime is 21001187. The next prime is 21001247. The reversal of 21001230 is 3210012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

21001230 is a modest number, since divided by 1230 gives 210 as remainder.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 116584 + ... + 116763.

It is an arithmetic number, because the mean of its divisors is an integer number (2275143).

Almost surely, 2^21001230 is an apocalyptic number.

21001230 is an abundant number, since it is smaller than the sum of its proper divisors (33602202).

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

21001230 is a wasteful number, since it uses less digits than its factorization.

21001230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233360 (or 233357 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 21001230 is about 4582.7098969933. The cubic root of 21001230 is about 275.8978040040.

Adding to 21001230 its reverse (3210012), we get a palindrome (24211242).

The spelling of 21001230 in words is "twenty-one million, one thousand, two hundred thirty".