20554021 has 8 divisors (see below), whose sum is σ = 20849400. Its totient is φ = 20260800.

The previous prime is 20554013. The next prime is 20554049. The reversal of 20554021 is 12045502.

It can be written as a sum of positive squares in 4 ways, for example, as 3629025 + 16924996 = 1905^2 + 4114^2 .

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 20554021 - 2³ = 20554013 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20554021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20554321) 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, 28971 + ... + 29671.

It is an arithmetic number, because the mean of its divisors is an integer number (2606175).

Almost surely, 2^20554021 is an apocalyptic number.

It is an amenable number.

20554021 is a deficient number, since it is larger than the sum of its proper divisors (295379).

20554021 is a wasteful number, since it uses less digits than its factorization.

20554021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1079.

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 20554021 is about 4533.6542656008. The cubic root of 20554021 is about 273.9253752767.

Adding to 20554021 its reverse (12045502), we get a palindrome (32599523).

The spelling of 20554021 in words is "twenty million, five hundred fifty-four thousand, twenty-one".