21106530 has 48 divisors (see below), whose sum is σ = 57769920. Its totient is φ = 5331744.

The previous prime is 21106523. The next prime is 21106531. The reversal of 21106530 is 3560112.

21106530 is a `hidden beast` number, since 2 + 1 + 10 + 653 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21106531) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4462 + ... + 7881.

It is an arithmetic number, because the mean of its divisors is an integer number (1203540).

Almost surely, 2^21106530 is an apocalyptic number.

21106530 is an abundant number, since it is smaller than the sum of its proper divisors (36663390).

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

21106530 is a wasteful number, since it uses less digits than its factorization.

21106530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12375 (or 12372 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 21106530 is about 4594.1843672191. The cubic root of 21106530 is about 276.3581519296.

Adding to 21106530 its reverse (3560112), we get a palindrome (24666642).

The spelling of 21106530 in words is "twenty-one million, one hundred six thousand, five hundred thirty".