1021211220 has 48 divisors (see below), whose sum is σ = 2957996160. Its totient is φ = 262932096.

The previous prime is 1021211209. The next prime is 1021211251. The reversal of 1021211220 is 221121201.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1021211196 and 1021211205.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 291712 + ... + 295191.

It is an arithmetic number, because the mean of its divisors is an integer number (61624920).

Almost surely, 2^1021211220 is an apocalyptic number.

1021211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021211220 is an abundant number, since it is smaller than the sum of its proper divisors (1936784940).

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

1021211220 is a wasteful number, since it uses less digits than its factorization.

1021211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 586944 (or 586942 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1021211220 is about 31956.3956040102. The cubic root of 1021211220 is about 1007.0209969039.

Adding to 1021211220 its reverse (221121201), we get a palindrome (1242332421).

The spelling of 1021211220 in words is "one billion, twenty-one million, two hundred eleven thousand, two hundred twenty".