1221230020 has 96 divisors (see below), whose sum is σ = 2827198080. Its totient is φ = 441047040.

The previous prime is 1221229993. The next prime is 1221230047. The reversal of 1221230020 is 200321221.

It is an interprime number because it is at equal distance from previous prime (1221229993) and next prime (1221230047).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2080167 + ... + 2080753.

It is an arithmetic number, because the mean of its divisors is an integer number (29449980).

Almost surely, 2^1221230020 is an apocalyptic number.

1221230020 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 1221230020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1413599040).

1221230020 is an abundant number, since it is smaller than the sum of its proper divisors (1605968060).

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

1221230020 is a wasteful number, since it uses less digits than its factorization.

1221230020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 853 (or 851 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 1221230020 is about 34946.1016423864. The cubic root of 1221230020 is about 1068.8887114285. Note that the first 3 decimals are identical.

Adding to 1221230020 its reverse (200321221), we get a palindrome (1421551241).

The spelling of 1221230020 in words is "one billion, two hundred twenty-one million, two hundred thirty thousand, twenty".