21135030 has 64 divisors (see below), whose sum is σ = 61032960. Its totient is φ = 4575744.

The previous prime is 21135013. The next prime is 21135031. The reversal of 21135030 is 3053112.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21135031) 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, 1342 + ... + 6638.

It is an arithmetic number, because the mean of its divisors is an integer number (953640).

Almost surely, 2^21135030 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21135030, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30516480).

21135030 is an abundant number, since it is smaller than the sum of its proper divisors (39897930).

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

21135030 is a wasteful number, since it uses less digits than its factorization.

21135030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5333.

The product of its (nonzero) digits is 90, while the sum is 15.

The square root of 21135030 is about 4597.2850683855. The cubic root of 21135030 is about 276.4824841454.

Adding to 21135030 its reverse (3053112), we get a palindrome (24188142).

The spelling of 21135030 in words is "twenty-one million, one hundred thirty-five thousand, thirty".