1021200012 has 72 divisors (see below), whose sum is σ = 2966745600. Its totient is φ = 290128608.

The previous prime is 1021199983. The next prime is 1021200017. The reversal of 1021200012 is 2100021201.

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 = 1021199967 and 1021200003.

It is not an unprimeable number, because it can be changed into a prime (1021200017) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33789 + ... + 56427.

It is an arithmetic number, because the mean of its divisors is an integer number (41204800).

Almost surely, 2^1021200012 is an apocalyptic number.

1021200012 is a gapful number since it is divisible by the number (12) 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 1021200012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1483372800).

1021200012 is an abundant number, since it is smaller than the sum of its proper divisors (1945545588).

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

1021200012 is a wasteful number, since it uses less digits than its factorization.

1021200012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22835 (or 22830 counting only the distinct ones).

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

The square root of 1021200012 is about 31956.2202395715. The cubic root of 1021200012 is about 1007.0173128039.

Adding to 1021200012 its reverse (2100021201), we get a palindrome (3121221213).

The spelling of 1021200012 in words is "one billion, twenty-one million, two hundred thousand, twelve".