1261224820 has 12 divisors (see below), whose sum is σ = 2648572164. Its totient is φ = 504489920.

The previous prime is 1261224779. The next prime is 1261224829. The reversal of 1261224820 is 284221621.

It can be written as a sum of positive squares in 2 ways, for example, as 138438756 + 1122786064 = 11766^2 + 33508^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261224829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31530601 + ... + 31530640.

It is an arithmetic number, because the mean of its divisors is an integer number (220714347).

Almost surely, 2^1261224820 is an apocalyptic number.

1261224820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261224820 is an abundant number, since it is smaller than the sum of its proper divisors (1387347344).

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

1261224820 is a wasteful number, since it uses less digits than its factorization.

1261224820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63061250 (or 63061248 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 1261224820 is about 35513.7272051245. The cubic root of 1261224820 is about 1080.4321601535.

The spelling of 1261224820 in words is "one billion, two hundred sixty-one million, two hundred twenty-four thousand, eight hundred twenty".