20211212221 has 8 divisors (see below), whose sum is σ = 20679881760. Its totient is φ = 19746746352.

The previous prime is 20211212207. The next prime is 20211212227. The reversal of 20211212221 is 12221211202.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20211212221 - 2¹³ = 20211204029 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20211212195 and 20211212204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211212227) 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, 1041190 + ... + 1060423.

It is an arithmetic number, because the mean of its divisors is an integer number (2584985220).

Almost surely, 2^20211212221 is an apocalyptic number.

It is an amenable number.

20211212221 is a deficient number, since it is larger than the sum of its proper divisors (468669539).

20211212221 is a wasteful number, since it uses less digits than its factorization.

20211212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2101835.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20211212221 its reverse (12221211202), we get a palindrome (32432423423).

The spelling of 20211212221 in words is "twenty billion, two hundred eleven million, two hundred twelve thousand, two hundred twenty-one".