1000021100 has 36 divisors (see below), whose sum is σ = 2336975424. Its totient is φ = 369238080.

The previous prime is 1000021097. The next prime is 1000021133. The reversal of 1000021100 is 11200001.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (5).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 383324 + ... + 385923.

It is an arithmetic number, because the mean of its divisors is an integer number (64915984).

Almost surely, 2^1000021100 is an apocalyptic number.

1000021100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1000021100 is an abundant number, since it is smaller than the sum of its proper divisors (1336954324).

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

1000021100 is a wasteful number, since it uses less digits than its factorization.

1000021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 769274 (or 769267 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 5.

The square root of 1000021100 is about 31623.1102202171. The cubic root of 1000021100 is about 1000.0070332839.

Adding to 1000021100 its reverse (11200001), we get a palindrome (1011221101).

The spelling of 1000021100 in words is "one billion, twenty-one thousand, one hundred".