1243242020 has 12 divisors (see below), whose sum is σ = 2610808284.
Its totient is φ = 497296800.
The previous prime is 1243242019. The next prime is 1243242031. The reversal of 1243242020 is 202423421.
It can be written as a sum of positive squares in 2 ways, for example, as 789722404 + 453519616 = 28102^2 + 21296^2
It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 62162101 = 1243242020 / (1 + 2 + 4 + 3 + 2 + 4 + 2 + 0 + 2 + 0).
It is a junction number, because it is equal to n+sod(n) for n = 1243241983 and 1243242001.
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31081031 + ... + 31081070.
It is an arithmetic number, because the mean of its divisors is an integer number (217567357).
Almost surely, 21243242020 is an apocalyptic number.
1243242020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is an amenable number.
1243242020 is an abundant number, since it is smaller than the sum of its proper divisors (1367566264).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1243242020 is a wasteful number, since it uses less digits than its factorization.
1243242020 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 62162110 (or 62162108 counting only the distinct ones).
The product of its (nonzero) digits is 768, while the sum is 20.
The square root of 1243242020 is about 35259.6372641580.
The cubic root of 1243242020 is about 1075.2725524892.
Adding to 1243242020 its reverse (202423421), we get a palindrome (1445665441).
The spelling of 1243242020 in words is "one billion, two hundred forty-three million, two hundred forty-two thousand, twenty".