1226821020 has 96 divisors (see below), whose sum is σ = 3536440320. Its totient is φ = 317640960.

The previous prime is 1226821009. The next prime is 1226821021. The reversal of 1226821020 is 201286221.

It is a super-2 number, since 2×1226821020² = 3010179630227680800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1226821021) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 287019 + ... + 291261.

It is an arithmetic number, because the mean of its divisors is an integer number (36837920).

Almost surely, 2^1226821020 is an apocalyptic number.

1226821020 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 1226821020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1768220160).

1226821020 is an abundant number, since it is smaller than the sum of its proper divisors (2309619300).

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

1226821020 is a wasteful number, since it uses less digits than its factorization.

1226821020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4395 (or 4393 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 1226821020 is about 35026.0049106375. The cubic root of 1226821020 is about 1070.5174135996.

The spelling of 1226821020 in words is "one billion, two hundred twenty-six million, eight hundred twenty-one thousand, twenty".