21316230 has 64 divisors (see below), whose sum is σ = 61225920. Its totient is φ = 5246208.

The previous prime is 21316223. The next prime is 21316231. The reversal of 21316230 is 3261312.

It is a super-2 number, since 2×21316230² = 908763322825800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21316231) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 474 + ... + 6546.

It is an arithmetic number, because the mean of its divisors is an integer number (956655).

Almost surely, 2^21316230 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21316230, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30612960).

21316230 is an abundant number, since it is smaller than the sum of its proper divisors (39909690).

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

21316230 is a wasteful number, since it uses less digits than its factorization.

21316230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6102 (or 6096 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 21316230 is about 4616.9502921301. The cubic root of 21316230 is about 277.2703724931.

Adding to 21316230 its reverse (3261312), we get a palindrome (24577542).

The spelling of 21316230 in words is "twenty-one million, three hundred sixteen thousand, two hundred thirty".