210121223220 has 72 divisors (see below), whose sum is σ = 646880698464. Its totient is φ = 55196019648.

The previous prime is 210121223189. The next prime is 210121223239. The reversal of 210121223220 is 22322121012.

210121223220 is a `hidden beast` number, since 210 + 1 + 212 + 23 + 220 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 210121223193 and 210121223202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8699434 + ... + 8723553.

Almost surely, 2^210121223220 is an apocalyptic number.

210121223220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

210121223220 is an abundant number, since it is smaller than the sum of its proper divisors (436759475244).

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

210121223220 is a wasteful number, since it uses less digits than its factorization.

210121223220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17423069 (or 17423064 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 210121223220 its reverse (22322121012), we get a palindrome (232443344232).

The spelling of 210121223220 in words is "two hundred ten billion, one hundred twenty-one million, two hundred twenty-three thousand, two hundred twenty".