201210721220 has 48 divisors (see below), whose sum is σ = 429225568128. Its totient is φ = 79215198720.

The previous prime is 201210721207. The next prime is 201210721241. The reversal of 201210721220 is 22127012102.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 201210721192 and 201210721201.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 712844 + ... + 954236.

It is an arithmetic number, because the mean of its divisors is an integer number (8942199336).

Almost surely, 2^201210721220 is an apocalyptic number.

201210721220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201210721220 is an abundant number, since it is smaller than the sum of its proper divisors (228014846908).

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

201210721220 is a wasteful number, since it uses less digits than its factorization.

201210721220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242060 (or 242058 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

Adding to 201210721220 its reverse (22127012102), we get a palindrome (223337733322).

The spelling of 201210721220 in words is "two hundred one billion, two hundred ten million, seven hundred twenty-one thousand, two hundred twenty".