1243641551 has 2 divisors, whose sum is σ = 1243641552. Its totient is φ = 1243641550.

The previous prime is 1243641541. The next prime is 1243641563. The reversal of 1243641551 is 1551463421.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1243641551 - 2³⁰ = 169899727 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243641541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621820775 + 621820776.

It is an arithmetic number, because the mean of its divisors is an integer number (621820776).

Almost surely, 2^1243641551 is an apocalyptic number.

1243641551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243641551 is an equidigital number, since it uses as much as digits as its factorization.

1243641551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 32.

The square root of 1243641551 is about 35265.3023664905. The cubic root of 1243641551 is about 1075.3877241399.

The spelling of 1243641551 in words is "one billion, two hundred forty-three million, six hundred forty-one thousand, five hundred fifty-one".