221001212212221 has 8 divisors (see below), whose sum is σ = 336763751942464. Its totient is φ = 126286406978400.

The previous prime is 221001212212189. The next prime is 221001212212267. The reversal of 221001212212221 is 122212212100122.

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

It is not a de Polignac number, because 221001212212221 - 2⁵ = 221001212212189 is a prime.

It is a super-2 number, since 2×221001212212221² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 10523867248201 = 221001212212221 / (2 + 2 + 1 + 0 + 0 + 1 + 2 + 1 + 2 + 2 + 1 + 2 + 2 + 2 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001212212721) 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, 5261933624080 + ... + 5261933624121.

It is an arithmetic number, because the mean of its divisors is an integer number (42095468992808).

Almost surely, 2^{221001212212221} is an apocalyptic number.

221001212212221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221001212212221 is a deficient number, since it is larger than the sum of its proper divisors (115762539730243).

221001212212221 is a wasteful number, since it uses less digits than its factorization.

221001212212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10523867248211.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 221001212212221 its reverse (122212212100122), we get a palindrome (343213424312343).

The spelling of 221001212212221 in words is "two hundred twenty-one trillion, one billion, two hundred twelve million, two hundred twelve thousand, two hundred twenty-one".