1243109551 has 2 divisors, whose sum is σ = 1243109552. Its totient is φ = 1243109550.

The previous prime is 1243109521. The next prime is 1243109603. The reversal of 1243109551 is 1559013421.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243109551 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243109521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621554775 + 621554776.

It is an arithmetic number, because the mean of its divisors is an integer number (621554776).

Almost surely, 2^1243109551 is an apocalyptic number.

1243109551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243109551 is an equidigital number, since it uses as much as digits as its factorization.

1243109551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 1243109551 is about 35257.7587347806. The cubic root of 1243109551 is about 1075.2343605854.

The spelling of 1243109551 in words is "one billion, two hundred forty-three million, one hundred nine thousand, five hundred fifty-one".