221021212120 has 32 divisors (see below), whose sum is σ = 513339592320. Its totient is φ = 85556597760.

The previous prime is 221021212117. The next prime is 221021212123. The reversal of 221021212120 is 21212120122.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (221021212117) and next prime (221021212123).

It is a junction number, because it is equal to n+sod(n) for n = 221021212094 and 221021212103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021212123) 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, 89120217 + ... + 89122696.

It is an arithmetic number, because the mean of its divisors is an integer number (16041862260).

Almost surely, 2^221021212120 is an apocalyptic number.

221021212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221021212120 is an abundant number, since it is smaller than the sum of its proper divisors (292318380200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221021212120 is a wasteful number, since it uses less digits than its factorization.

221021212120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178242955 (or 178242951 counting only the distinct ones).

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

Adding to 221021212120 its reverse (21212120122), we get a palindrome (242233332242).

The spelling of 221021212120 in words is "two hundred twenty-one billion, twenty-one million, two hundred twelve thousand, one hundred twenty".