1243316551 has 4 divisors (see below), whose sum is σ = 1244282400. Its totient is φ = 1242350704.

The previous prime is 1243316549. The next prime is 1243316563. The reversal of 1243316551 is 1556133421.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1243316551 - 2¹ = 1243316549 is a prime.

It is a super-3 number, since 3×1243316551³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243316351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 480991 + ... + 483568.

It is an arithmetic number, because the mean of its divisors is an integer number (311070600).

Almost surely, 2^1243316551 is an apocalyptic number.

1243316551 is a deficient number, since it is larger than the sum of its proper divisors (965849).

1243316551 is an equidigital number, since it uses as much as digits as its factorization.

1243316551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 965848.

The product of its digits is 10800, while the sum is 31.

The square root of 1243316551 is about 35260.6941366729. The cubic root of 1243316551 is about 1075.2940391979.

Adding to 1243316551 its reverse (1556133421), we get a palindrome (2799449972).

The spelling of 1243316551 in words is "one billion, two hundred forty-three million, three hundred sixteen thousand, five hundred fifty-one".