1242205220 has 24 divisors (see below), whose sum is σ = 2651398008. Its totient is φ = 488736000.

The previous prime is 1242205207. The next prime is 1242205267. The reversal of 1242205220 is 225022421.

It can be written as a sum of positive squares in 4 ways, for example, as 95570176 + 1146635044 = 9776^2 + 33862^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1242205192 and 1242205201.

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, 507881 + ... + 510320.

It is an arithmetic number, because the mean of its divisors is an integer number (110474917).

Almost surely, 2^1242205220 is an apocalyptic number.

1242205220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1242205220 is an abundant number, since it is smaller than the sum of its proper divisors (1409192788).

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

1242205220 is a wasteful number, since it uses less digits than its factorization.

1242205220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1018271 (or 1018269 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 1242205220 is about 35244.9318342368. The cubic root of 1242205220 is about 1074.9735619963.

Adding to 1242205220 its reverse (225022421), we get a palindrome (1467227641).

The spelling of 1242205220 in words is "one billion, two hundred forty-two million, two hundred five thousand, two hundred twenty".