21635130 has 64 divisors (see below), whose sum is σ = 57760128. Its totient is φ = 5141760.

The previous prime is 21635069. The next prime is 21635137. The reversal of 21635130 is 3153612.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21635097 and 21635106.

It is not an unprimeable number, because it can be changed into a prime (21635137) 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, 16872 + ... + 18108.

It is an arithmetic number, because the mean of its divisors is an integer number (902502).

Almost surely, 2^21635130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21635130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28880064).

21635130 is an abundant number, since it is smaller than the sum of its proper divisors (36124998).

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

21635130 is a wasteful number, since it uses less digits than its factorization.

21635130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1311.

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 21635130 is about 4651.3578662580. The cubic root of 21635130 is about 278.6462288097.

Adding to 21635130 its reverse (3153612), we get a palindrome (24788742).

The spelling of 21635130 in words is "twenty-one million, six hundred thirty-five thousand, one hundred thirty".