21042576 has 60 divisors (see below), whose sum is σ = 61997520. Its totient is φ = 6644160.

The previous prime is 21042563. The next prime is 21042577. The reversal of 21042576 is 67524012.

It is not an unprimeable number, because it can be changed into a prime (21042577) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1110 + ... + 6581.

It is an arithmetic number, because the mean of its divisors is an integer number (1033292).

Almost surely, 2^21042576 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21042576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30998760).

21042576 is an abundant number, since it is smaller than the sum of its proper divisors (40954944).

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

21042576 is a wasteful number, since it uses less digits than its factorization.

21042576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7724 (or 7715 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 21042576 is about 4587.2187652215. The cubic root of 21042576 is about 276.0787424981.

Adding to 21042576 its reverse (67524012), we get a palindrome (88566588).

The spelling of 21042576 in words is "twenty-one million, forty-two thousand, five hundred seventy-six".