1251326551 has 2 divisors, whose sum is σ = 1251326552. Its totient is φ = 1251326550.

The previous prime is 1251326521. The next prime is 1251326591. The reversal of 1251326551 is 1556231521.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1251326551 - 2¹⁹ = 1250802263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1251326521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625663275 + 625663276.

It is an arithmetic number, because the mean of its divisors is an integer number (625663276).

Almost surely, 2^1251326551 is an apocalyptic number.

1251326551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251326551 is an equidigital number, since it uses as much as digits as its factorization.

1251326551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9000, while the sum is 31.

The square root of 1251326551 is about 35374.0943488310. The cubic root of 1251326551 is about 1077.5982726281.

The spelling of 1251326551 in words is "one billion, two hundred fifty-one million, three hundred twenty-six thousand, five hundred fifty-one".