1243655855 has 8 divisors (see below), whose sum is σ = 1607186112. Its totient is φ = 918391968.

The previous prime is 1243655851. The next prime is 1243655857. The reversal of 1243655855 is 5585563421.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1243655855 - 2² = 1243655851 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243655851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9566519 + ... + 9566648.

It is an arithmetic number, because the mean of its divisors is an integer number (200898264).

Almost surely, 2^1243655855 is an apocalyptic number.

1243655855 is a deficient number, since it is larger than the sum of its proper divisors (363530257).

1243655855 is a wasteful number, since it uses less digits than its factorization.

1243655855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19133185.

The product of its digits is 720000, while the sum is 44.

The square root of 1243655855 is about 35265.5051714845. The cubic root of 1243655855 is about 1075.3918470554.

The spelling of 1243655855 in words is "one billion, two hundred forty-three million, six hundred fifty-five thousand, eight hundred fifty-five".