221010221212221 has 64 divisors (see below), whose sum is σ = 340951278666240. Its totient is φ = 124734206361600.

The previous prime is 221010221212219. The next prime is 221010221212283. The reversal of 221010221212221 is 122212122010122.

It is not a de Polignac number, because 221010221212221 - 2¹ = 221010221212219 is a prime.

It is a super-2 number, since 2×221010221212221² (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).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221010221212201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1333609861 + ... + 1333775573.

It is an arithmetic number, because the mean of its divisors is an integer number (5327363729160).

Almost surely, 2^{221010221212221} is an apocalyptic number.

221010221212221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221010221212221 is a deficient number, since it is larger than the sum of its proper divisors (119941057454019).

221010221212221 is a wasteful number, since it uses less digits than its factorization.

221010221212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167686.

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

Adding to 221010221212221 its reverse (122212122010122), we get a palindrome (343222343222343).

The spelling of 221010221212221 in words is "two hundred twenty-one trillion, ten billion, two hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".