1021220100 has 108 divisors (see below), whose sum is σ = 3219155940. Its totient is φ = 270777600.

The previous prime is 1021220099. The next prime is 1021220119. The reversal of 1021220100 is 10221201.

1021220100 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 302551236 + 718668864 = 17394^2 + 26808^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 159766 + ... + 166034.

Almost surely, 2^1021220100 is an apocalyptic number.

1021220100 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 1021220100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1609577970).

1021220100 is an abundant number, since it is smaller than the sum of its proper divisors (2197935840).

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

1021220100 is a wasteful number, since it uses less digits than its factorization.

1021220100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6470 (or 6460 counting only the distinct ones).

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

The square root of 1021220100 is about 31956.5345430320. The cubic root of 1021220100 is about 1007.0239157648.

Adding to 1021220100 its reverse (10221201), we get a palindrome (1031441301).

The spelling of 1021220100 in words is "one billion, twenty-one million, two hundred twenty thousand, one hundred".