20208621 has 32 divisors (see below), whose sum is σ = 29491200. Its totient is φ = 12277440.

The previous prime is 20208619. The next prime is 20208641. The reversal of 20208621 is 12680202.

It is not a de Polignac number, because 20208621 - 2¹ = 20208619 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 (20208611) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159060 + ... + 159186.

It is an arithmetic number, because the mean of its divisors is an integer number (921600).

Almost surely, 2^20208621 is an apocalyptic number.

It is an amenable number.

20208621 is a deficient number, since it is larger than the sum of its proper divisors (9282579).

20208621 is a wasteful number, since it uses less digits than its factorization.

20208621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 20208621 is about 4495.3999822040. The cubic root of 20208621 is about 272.3823064402.

Adding to 20208621 its reverse (12680202), we get a palindrome (32888823).

The spelling of 20208621 in words is "twenty million, two hundred eight thousand, six hundred twenty-one".