1021311220 has 24 divisors (see below), whose sum is σ = 2150949024. Its totient is φ = 407344416.

The previous prime is 1021311211. The next prime is 1021311281. The reversal of 1021311220 is 221131201.

It is a self number, because there is not a number n which added to its sum of digits gives 1021311220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66642 + ... + 80521.

It is an arithmetic number, because the mean of its divisors is an integer number (89622876).

Almost surely, 2^1021311220 is an apocalyptic number.

1021311220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021311220 is an abundant number, since it is smaller than the sum of its proper divisors (1129637804).

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

1021311220 is a wasteful number, since it uses less digits than its factorization.

1021311220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147519 (or 147517 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1021311220 is about 31957.9601977348. The cubic root of 1021311220 is about 1007.0538659816.

Adding to 1021311220 its reverse (221131201), we get a palindrome (1242442421).

The spelling of 1021311220 in words is "one billion, twenty-one million, three hundred eleven thousand, two hundred twenty".