21560364 has 144 divisors (see below), whose sum is σ = 68275200. Its totient is φ = 5762016.

The previous prime is 21560359. The next prime is 21560377. The reversal of 21560364 is 46306512.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 272877 + ... + 272955.

Almost surely, 2^21560364 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 21560364, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34137600).

21560364 is an abundant number, since it is smaller than the sum of its proper divisors (46714836).

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

21560364 is a wasteful number, since it uses less digits than its factorization.

21560364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 110 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 21560364 is about 4643.3139028069. The cubic root of 21560364 is about 278.3248794051.

Adding to 21560364 its reverse (46306512), we get a palindrome (67866876).

The spelling of 21560364 in words is "twenty-one million, five hundred sixty thousand, three hundred sixty-four".