21000568 has 8 divisors (see below), whose sum is σ = 39376080. Its totient is φ = 10500280.

The previous prime is 21000563. The next prime is 21000583. The reversal of 21000568 is 86500012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1312528 + ... + 1312543.

It is an arithmetic number, because the mean of its divisors is an integer number (4922010).

Almost surely, 2^21000568 is an apocalyptic number.

It is an amenable number.

21000568 is a deficient number, since it is larger than the sum of its proper divisors (18375512).

21000568 is a wasteful number, since it uses less digits than its factorization.

21000568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2625077 (or 2625073 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 21000568 is about 4582.6376684176. The cubic root of 21000568 is about 275.8949050267.

The spelling of 21000568 in words is "twenty-one million, five hundred sixty-eight", and thus it is an aban number.