1201021800 has 288 divisors, whose sum is σ = 4167858240. Its totient is φ = 285824000.

The previous prime is 1201021799. The next prime is 1201021847. The reversal of 1201021800 is 81201021.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1201021800.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 5154484 + ... + 5154716.

It is an arithmetic number, because the mean of its divisors is an integer number (14471730).

Almost surely, 2^1201021800 is an apocalyptic number.

1201021800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1201021800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2083929120).

1201021800 is an abundant number, since it is smaller than the sum of its proper divisors (2966836440).

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

1201021800 is a wasteful number, since it uses less digits than its factorization.

1201021800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 1201021800 is about 34655.7614257716. The cubic root of 1201021800 is about 1062.9601015378.

Adding to 1201021800 its reverse (81201021), we get a palindrome (1282222821).

The spelling of 1201021800 in words is "one billion, two hundred one million, twenty-one thousand, eight hundred".