20005551021 has 8 divisors (see below), whose sum is σ = 26676478080. Its totient is φ = 13335828992.

The previous prime is 20005551011. The next prime is 20005551037. The reversal of 20005551021 is 12015550002.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20005551021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20005551001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261780 + ... + 329453.

It is an arithmetic number, because the mean of its divisors is an integer number (3334559760).

Almost surely, 2^20005551021 is an apocalyptic number.

It is an amenable number.

20005551021 is a deficient number, since it is larger than the sum of its proper divisors (6670927059).

20005551021 is a wasteful number, since it uses less digits than its factorization.

20005551021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602515.

The product of its (nonzero) digits is 500, while the sum is 21.

The spelling of 20005551021 in words is "twenty billion, five million, five hundred fifty-one thousand, twenty-one".