20400220221 has 8 divisors (see below), whose sum is σ = 27201590400. Its totient is φ = 13599498432.

The previous prime is 20400220213. The next prime is 20400220223. The reversal of 20400220221 is 12202200402.

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

It is not a de Polignac number, because 20400220221 - 2³ = 20400220213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20400220221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400220223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83196 + ... + 218453.

It is an arithmetic number, because the mean of its divisors is an integer number (3400198800).

Almost surely, 2^20400220221 is an apocalyptic number.

It is an amenable number.

20400220221 is a deficient number, since it is larger than the sum of its proper divisors (6801370179).

20400220221 is a wasteful number, since it uses less digits than its factorization.

20400220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324195.

The product of its (nonzero) digits is 128, while the sum is 15.

Adding to 20400220221 its reverse (12202200402), we get a palindrome (32602420623).

The spelling of 20400220221 in words is "twenty billion, four hundred million, two hundred twenty thousand, two hundred twenty-one".