21036576 has 72 divisors (see below), whose sum is σ = 60730992. Its totient is φ = 6371200.

The previous prime is 21036563. The next prime is 21036577. The reversal of 21036576 is 67563012.

It is not an unprimeable number, because it can be changed into a prime (21036577) 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, 10711 + ... + 12521.

It is an arithmetic number, because the mean of its divisors is an integer number (843486).

Almost surely, 2^21036576 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 21036576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30365496).

21036576 is an abundant number, since it is smaller than the sum of its proper divisors (39694416).

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

21036576 is a wasteful number, since it uses less digits than its factorization.

21036576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1846 (or 1827 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 30.

The square root of 21036576 is about 4586.5647275494. The cubic root of 21036576 is about 276.0524999899.

Adding to 21036576 its reverse (67563012), we get a palindrome (88599588).

It can be divided in two parts, 21036 and 576, that added together give a palindrome (21612).

The spelling of 21036576 in words is "twenty-one million, thirty-six thousand, five hundred seventy-six".