1021212220 has 24 divisors (see below), whose sum is σ = 2450909664. Its totient is φ = 350129856.

The previous prime is 1021212211. The next prime is 1021212233. The reversal of 1021212220 is 222121201.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1021212220.

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 7 ways as a sum of consecutive naturals, for example, 3647047 + ... + 3647326.

It is an arithmetic number, because the mean of its divisors is an integer number (102121236).

Almost surely, 2^1021212220 is an apocalyptic number.

1021212220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021212220 is an abundant number, since it is smaller than the sum of its proper divisors (1429697444).

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

1021212220 is a wasteful number, since it uses less digits than its factorization.

1021212220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7294389 (or 7294387 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1021212220 is about 31956.4112503266. The cubic root of 1021212220 is about 1007.0213256053.

Adding to 1021212220 its reverse (222121201), we get a palindrome (1243333421).

The spelling of 1021212220 in words is "one billion, twenty-one million, two hundred twelve thousand, two hundred twenty".