10821564 has 72 divisors (see below), whose sum is σ = 31034640. Its totient is φ = 3151872.

The previous prime is 10821541. The next prime is 10821589. The reversal of 10821564 is 46512801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8284 + ... + 9500.

Almost surely, 2^10821564 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 10821564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15517320).

10821564 is an abundant number, since it is smaller than the sum of its proper divisors (20213076).

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

10821564 is a wasteful number, since it uses less digits than its factorization.

10821564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1259 (or 1254 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 10821564 is about 3289.6145670884. The cubic root of 10821564 is about 221.1889077711.

The spelling of 10821564 in words is "ten million, eight hundred twenty-one thousand, five hundred sixty-four".