1243156749 has 8 divisors (see below), whose sum is σ = 1673635392. Its totient is φ = 820724640.

The previous prime is 1243156741. The next prime is 1243156771. The reversal of 1243156749 is 9476513421.

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

It is not a de Polignac number, because 1243156749 - 2³ = 1243156741 is a prime.

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 1243156749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243156741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2011272 + ... + 2011889.

It is an arithmetic number, because the mean of its divisors is an integer number (209204424).

Almost surely, 2^1243156749 is an apocalyptic number.

It is an amenable number.

1243156749 is a deficient number, since it is larger than the sum of its proper divisors (430478643).

1243156749 is a wasteful number, since it uses less digits than its factorization.

1243156749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4023267.

The product of its digits is 181440, while the sum is 42.

The square root of 1243156749 is about 35258.4280562818. The cubic root of 1243156749 is about 1075.2479684687.

The spelling of 1243156749 in words is "one billion, two hundred forty-three million, one hundred fifty-six thousand, seven hundred forty-nine".