1243055993 has 4 divisors (see below), whose sum is σ = 1243130100. Its totient is φ = 1242981888.

The previous prime is 1243055941. The next prime is 1243056043. The reversal of 1243055993 is 3995503421.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 929518144 + 313537849 = 30488^2 + 17707^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243055993 - 2¹² = 1243051897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1243055993.

It is not an unprimeable number, because it can be changed into a prime (1243015993) 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, 1433 + ... + 49881.

It is an arithmetic number, because the mean of its divisors is an integer number (310782525).

Almost surely, 2^1243055993 is an apocalyptic number.

It is an amenable number.

1243055993 is a deficient number, since it is larger than the sum of its proper divisors (74107).

1243055993 is an equidigital number, since it uses as much as digits as its factorization.

1243055993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74106.

The product of its (nonzero) digits is 145800, while the sum is 41.

The square root of 1243055993 is about 35256.9992058315. Note that the first 3 decimals coincide. The cubic root of 1243055993 is about 1075.2189186026.

The spelling of 1243055993 in words is "one billion, two hundred forty-three million, fifty-five thousand, nine hundred ninety-three".