1243821020 has 48 divisors (see below), whose sum is σ = 2909964960. Its totient is φ = 443417856.

The previous prime is 1243821017. The next prime is 1243821083. The reversal of 1243821020 is 201283421.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74942 + ... + 90021.

It is an arithmetic number, because the mean of its divisors is an integer number (60624270).

Almost surely, 2^1243821020 is an apocalyptic number.

1243821020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1243821020 is an abundant number, since it is smaller than the sum of its proper divisors (1666143940).

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

1243821020 is a wasteful number, since it uses less digits than its factorization.

1243821020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165014 (or 165012 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 1243821020 is about 35267.8468296549. The cubic root of 1243821020 is about 1075.4394511229.

The spelling of 1243821020 in words is "one billion, two hundred forty-three million, eight hundred twenty-one thousand, twenty".