21601230 has 64 divisors (see below), whose sum is σ = 61309440. Its totient is φ = 4765824.

The previous prime is 21601189. The next prime is 21601277. The reversal of 21601230 is 3210612.

It is a super-2 number, since 2×21601230² = 933226275025800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4317 + ... + 7863.

It is an arithmetic number, because the mean of its divisors is an integer number (957960).

Almost surely, 2^21601230 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21601230, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30654720).

21601230 is an abundant number, since it is smaller than the sum of its proper divisors (39708210).

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

21601230 is a wasteful number, since it uses less digits than its factorization.

21601230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3593.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21601230 is about 4647.7123404961. The cubic root of 21601230 is about 278.5006161704.

Adding to 21601230 its reverse (3210612), we get a palindrome (24811842).

The spelling of 21601230 in words is "twenty-one million, six hundred one thousand, two hundred thirty".