20900506221 has 40 divisors (see below), whose sum is σ = 35750725824. Its totient is φ = 11920141440.

The previous prime is 20900506139. The next prime is 20900506223. The reversal of 20900506221 is 12260500902.

It is not a de Polignac number, because 20900506221 - 2⁹ = 20900505709 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20900506223) 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 39 ways as a sum of consecutive naturals, for example, 261301 + ... + 331781.

Almost surely, 2^20900506221 is an apocalyptic number.

20900506221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20900506221 is a deficient number, since it is larger than the sum of its proper divisors (14850219603).

20900506221 is an equidigital number, since it uses as much as digits as its factorization.

20900506221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71023 (or 71014 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The spelling of 20900506221 in words is "twenty billion, nine hundred million, five hundred six thousand, two hundred twenty-one".