21315230 has 32 divisors (see below), whose sum is σ = 39559968. Its totient is φ = 8265600.

The previous prime is 21315223. The next prime is 21315241. The reversal of 21315230 is 3251312.

It is a junction number, because it is equal to n+sod(n) for n = 21315199 and 21315208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50420 + ... + 50840.

It is an arithmetic number, because the mean of its divisors is an integer number (1236249).

Almost surely, 2^21315230 is an apocalyptic number.

21315230 is a deficient number, since it is larger than the sum of its proper divisors (18244738).

21315230 is a wasteful number, since it uses less digits than its factorization.

21315230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21315230 is about 4616.8419942640. The cubic root of 21315230 is about 277.2660365996.

Adding to 21315230 its reverse (3251312), we get a palindrome (24566542).

The spelling of 21315230 in words is "twenty-one million, three hundred fifteen thousand, two hundred thirty".