21300661 has 8 divisors (see below), whose sum is σ = 21571424. Its totient is φ = 21031920.

The previous prime is 21300659. The next prime is 21300673. The reversal of 21300661 is 16600312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21300661 - 2¹ = 21300659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32806 + ... + 33448.

It is an arithmetic number, because the mean of its divisors is an integer number (2696428).

Almost surely, 2^21300661 is an apocalyptic number.

It is an amenable number.

21300661 is a deficient number, since it is larger than the sum of its proper divisors (270763).

21300661 is a wasteful number, since it uses less digits than its factorization.

21300661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1011.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 21300661 is about 4615.2639144474. The cubic root of 21300661 is about 277.2028515817.

Adding to 21300661 its reverse (16600312), we get a palindrome (37900973).

The spelling of 21300661 in words is "twenty-one million, three hundred thousand, six hundred sixty-one".