21530076 has 24 divisors (see below), whose sum is σ = 50453760. Its totient is φ = 7145712.

The previous prime is 21530017. The next prime is 21530077. The reversal of 21530076 is 67003512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 886 + ... + 6621.

It is an arithmetic number, because the mean of its divisors is an integer number (2102240).

Almost surely, 2^21530076 is an apocalyptic number.

It is an amenable number.

21530076 is an abundant number, since it is smaller than the sum of its proper divisors (28923684).

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

21530076 is a wasteful number, since it uses less digits than its factorization.

21530076 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7753 (or 7751 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 24.

The square root of 21530076 is about 4640.0512928199. The cubic root of 21530076 is about 278.1944880617.

Adding to 21530076 its reverse (67003512), we get a palindrome (88533588).

The spelling of 21530076 in words is "twenty-one million, five hundred thirty thousand, seventy-six".