1021211100 has 432 divisors, whose sum is σ = 4058087488. Its totient is φ = 209018880.

The previous prime is 1021211033. The next prime is 1021211129. The reversal of 1021211100 is 11121201.

It is a happy number.

It is a super-2 number, since 2×1021211100² = 2085744221526420000, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 3030132 + ... + 3030468.

Almost surely, 2^1021211100 is an apocalyptic number.

1021211100 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 1021211100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2029043744).

1021211100 is an abundant number, since it is smaller than the sum of its proper divisors (3036876388).

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

1021211100 is a wasteful number, since it uses less digits than its factorization.

1021211100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414 (or 404 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 1021211100 is about 31956.3937264517. The cubic root of 1021211100 is about 1007.0209574597.

Adding to 1021211100 its reverse (11121201), we get a palindrome (1032332301).

It can be divided in two parts, 10212 and 11100, that added together give a palindrome (21312).

The spelling of 1021211100 in words is "one billion, twenty-one million, two hundred eleven thousand, one hundred".