1021221100 has 36 divisors (see below), whose sum is σ = 2238013008. Its totient is φ = 404440000.

The previous prime is 1021221077. The next prime is 1021221133. The reversal of 1021221100 is 11221201.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40456 + ... + 60655.

It is an arithmetic number, because the mean of its divisors is an integer number (62167028).

Almost surely, 2^1021221100 is an apocalyptic number.

1021221100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021221100 is an abundant number, since it is smaller than the sum of its proper divisors (1216791908).

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

1021221100 is a wasteful number, since it uses less digits than its factorization.

1021221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101226 (or 101219 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1021221100 is about 31956.5501892804. The cubic root of 1021221100 is about 1007.0242444643.

Adding to 1021221100 its reverse (11221201), we get a palindrome (1032442301).

The spelling of 1021221100 in words is "one billion, twenty-one million, two hundred twenty-one thousand, one hundred".