20210101221 has 16 divisors (see below), whose sum is σ = 27322764480. Its totient is φ = 13286232960.

The previous prime is 20210101217. The next prime is 20210101229. The reversal of 20210101221 is 12210101202.

It is not a de Polignac number, because 20210101221 - 2² = 20210101217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20210101197 and 20210101206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20210101229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1875 + ... + 201056.

It is an arithmetic number, because the mean of its divisors is an integer number (1707672780).

Almost surely, 2^20210101221 is an apocalyptic number.

It is an amenable number.

20210101221 is a deficient number, since it is larger than the sum of its proper divisors (7112663259).

20210101221 is a wasteful number, since it uses less digits than its factorization.

20210101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203396.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20210101221 its reverse (12210101202), we get a palindrome (32420202423).

The spelling of 20210101221 in words is "twenty billion, two hundred ten million, one hundred one thousand, two hundred twenty-one".