20211031221 has 32 divisors (see below), whose sum is σ = 27841658880. Its totient is φ = 13033353600.

The previous prime is 20211031189. The next prime is 20211031249. The reversal of 20211031221 is 12213011202.

It is not a de Polignac number, because 20211031221 - 2⁵ = 20211031189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20211031221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211031021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7431900 + ... + 7434618.

It is an arithmetic number, because the mean of its divisors is an integer number (870051840).

Almost surely, 2^20211031221 is an apocalyptic number.

It is an amenable number.

20211031221 is a deficient number, since it is larger than the sum of its proper divisors (7630627659).

20211031221 is a wasteful number, since it uses less digits than its factorization.

20211031221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3257.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 20211031221 its reverse (12213011202), we get a palindrome (32424042423).

The spelling of 20211031221 in words is "twenty billion, two hundred eleven million, thirty-one thousand, two hundred twenty-one".