1200021210 has 128 divisors (see below), whose sum is σ = 3355672320. Its totient is φ = 304819200.

The previous prime is 1200021187. The next prime is 1200021217. The reversal of 1200021210 is 121200021.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 1200021192 and 1200021201.

It is not an unprimeable number, because it can be changed into a prime (1200021217) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 474750 + ... + 477270.

It is an arithmetic number, because the mean of its divisors is an integer number (26216190).

Almost surely, 2^1200021210 is an apocalyptic number.

1200021210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1200021210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1677836160).

1200021210 is an abundant number, since it is smaller than the sum of its proper divisors (2155651110).

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

1200021210 is a wasteful number, since it uses less digits than its factorization.

1200021210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2621 (or 2615 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1200021210 is about 34641.3222900050. The cubic root of 1200021210 is about 1062.6648299758.

Adding to 1200021210 its reverse (121200021), we get a palindrome (1321221231).

The spelling of 1200021210 in words is "one billion, two hundred million, twenty-one thousand, two hundred ten".