20730621 has 16 divisors (see below), whose sum is σ = 28742400. Its totient is φ = 13274688.

The previous prime is 20730607. The next prime is 20730623. The reversal of 20730621 is 12603702.

It is a happy number.

It is not a de Polignac number, because 20730621 - 2⁹ = 20730109 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20730623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20295 + ... + 21291.

It is an arithmetic number, because the mean of its divisors is an integer number (1796400).

Almost surely, 2^20730621 is an apocalyptic number.

It is an amenable number.

20730621 is a deficient number, since it is larger than the sum of its proper divisors (8011779).

20730621 is a wasteful number, since it uses less digits than its factorization.

20730621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1268.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 20730621 is about 4553.0891711013. The cubic root of 20730621 is about 274.7076606881.

The spelling of 20730621 in words is "twenty million, seven hundred thirty thousand, six hundred twenty-one".