20531242221 has 8 divisors (see below), whose sum is σ = 31285702464. Its totient is φ = 11732138400.

The previous prime is 20531242219. The next prime is 20531242253. The reversal of 20531242221 is 12224213502.

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

It is not a de Polignac number, because 20531242221 - 2¹ = 20531242219 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20531242191 and 20531242200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20531242211) 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, 488839080 + ... + 488839121.

It is an arithmetic number, because the mean of its divisors is an integer number (3910712808).

Almost surely, 2^20531242221 is an apocalyptic number.

20531242221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20531242221 is a deficient number, since it is larger than the sum of its proper divisors (10754460243).

20531242221 is an equidigital number, since it uses as much as digits as its factorization.

20531242221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 977678211.

The product of its (nonzero) digits is 1920, while the sum is 24.

Adding to 20531242221 its reverse (12224213502), we get a palindrome (32755455723).

The spelling of 20531242221 in words is "twenty billion, five hundred thirty-one million, two hundred forty-two thousand, two hundred twenty-one".